TECHNICAL FIELD The present disclosure relates to pharmacologically active l-((2,3-dihydrobenzo[b][l,4]-dioxin-2-yl)methyl)piperidine derivatives, or pharmaceutically acceptable salts and esters thereof, as well as to pharmaceutical compositions comprising them and to their use as alpha2C antagonists. BACKGROUND OF THE INVENTION It is generally known and accepted in the art that compounds exhibiting alpha adrenergic activity may be used for the treatment of a wide variety of diseases and conditions of the peripheric system and the central nervous system (CNS). The alpha adrenergic receptors can be divided on a pharmacological basis into alpha 1 and alpha2 adrenoceptors, which can both be further divided into subtypes. Three genetically encoded subtypes, namely alpha2A, alpha2B, and alpha2C adrenoceptors, have been discovered in human. A fourth pharmacologically defined subtype, namely alpha2D adrenoceptor, is known in some other mammals and in rodents. It corresponds to the genetically defined alpha2A adrenoceptor. The alpha2 adrenoceptor subtypes have distinct tissue distributions and functional roles. For instance, while alpha2A adrenoceptors are widely expressed in various tissues, alpha2C adrenoceptors are concentrated in the CNS and appear to play a role in the modulation of specific CNS mediated behavioral and physiological responses. Some compounds that are non-specific for any of the above-mentioned alpha2 subtypes and some compounds that are specific for certain alpha2 subtypes are known in the art. For example, atipamezole disclosed in EP 183 492 is a non-specific alpha2 antagonist. Compounds that are selective antagonists for the alpha2C subtype and are thus useful for the treatment of diseases of the central nervous system, are described, for example in WO 2009/013390 and WO 2010/058060. In order to be able to reduce the risk of adverse events during treatment, an enhanced selectivity of the alpha2 antagonists would be desirable. For example, the use of non- selective alpha2 antagonists is attributed with side effects, such as increases in blood pressure, heart rate, salivary secretion, gastrointestinal secretion, and anxiety. Also an enhanced potency of the alpha2C antagonists would be desirable, in order to be able to reduce the dose needed. SUMMARY OF THE INVENTION An object of the present disclosure is to provide novel alpha2C antagonists that can be used for the treatment of diseases or conditions of the peripheric or central nervous system wherein alpha2C antagonists are indicated to be useful. Accordingly, an object of the present disclosure is to provide further compounds to be used as alpha2C antagonists in the treatment of mammals. Furthermore, pharmaceutical compositions comprising the presently disclosed compounds are also provided. The alpha2 antagonists of the present disclosure have an improved selectivity for the alpha2C adrenoceptor subtype, an enhanced potency, improved metabolic stability, and/or improved solubility, moreover, more desirable pharmacokinetic and pharmacodynamics. DETAILED DESCRIPTION OF THE INVENTION The present disclosure relates to novel compounds having the general formula I, wherein; Ra and R, form, together with the nitrogen atom to which they are attached, a 5 or 6 membered saturated or unsaturated heterocyclic ring, containing, in addition to the nitrogen atom to which Ra and R, are attached, 0, 1 or 2 ring heteroatom(s) each independently selected from N, O and S, wherein said heterocyclic ring is substituted with 1 substituent Ri, or said heterocyclic ring is substituted with 2 substituents Ri and R2, or said heterocyclic ring is substituted with 3 substituents Ri, R2, and R3, or said heterocyclic ring is substituted with 4 substituents Ri, R2, R3, and R4, or said heterocyclic ring is substituted with 5 substituents Ri, R2, R3, R4, and R5; Ri, R2, R3, R4 and R5 are independently oxo, (Ci-C6)alkyl, (Ci-C6)alkoxy(Ci-C6)alkyl, (¾6)2Ν-, (R6)2N-(C1-C6)alkyl, (R6)2N-(C=0)-(C1-C6)alkyl, (C1-C6)alkyl-(C=0)-NR6-(C1-C6)alkyl, cyclo(C3-C6)alkyl, cyclo(C3-C6)alkyl(Ci-C6)alkyl, phenyl, phenyl(Ci-C6)alkyl, heterocyclyl, or heterocyclyl(Ci-C6)alkyl, wherein said phenyl, cyclo(C3-C6)alkyl, or heterocyclyl is optionally substituted with 1 or 2 substituent(s) each independenty being halogen, (Ci-C6)alkoxy, or (Ci-C6)alkyl-(C=0); or two of R3, R4 and R5, both attached to the same carbon ring atom form, together with the carbon ring atom to which they are attached, a 3 membered unsubstituted carbocyclic ring; or two of Ri, R2, R3, R4 and R5, attached to the adjacent carbon ring atoms form, together with the carbon ring atoms to which they are attached, a phenyl ring, a 3 to 6 membered saturated or unsaturated carbocyclic ring, or a 5 or 6 membered saturated or unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N and S, wherein said phenyl ring, carbocyclic ring, or heterocyclic ring is unsubstituted, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 2 substituents R7 and R8; Re is H or (Ci-C6)alkyl; R7 and R8 are independently halogen, (Ci-C6)alkyl, (d-C6)alkoxy, (Ci-C6)alkyl-S-, CN, or (Ci-C6)alkyl-(C=0)-NR6-(Ci-C6)alkyl; or R7 and Rg, attached to the non-adjacent carbon ring atoms, form a bridge; or a pharmaceutically acceptable salt or ester thereof. In one embodiment the present disclosure relates to compounds of formula I, wherein the mpound is a compound of formula la, In one embodiment the present disclosure relates to compounds of formula I, wherein; Ra and R, form, together with the nitrogen atom to which they are attached, a 5 or 6 membered saturated or unsaturated heterocyclic ring, containing, in addition to the nitrogen atom to which Ra and R, are attached, 0, 1 or 2 ring heteroatom(s) each independently selected from N, O and S, wherein said heterocyclic ring is substituted with 1 substituent Ri, or said heterocyclic ring is substituted with 2 substituents Ri and R2, or said heterocyclic ring is substituted with 3 substituents Ri, R2, and R3, or said heterocyclic ring is substituted with 4 substituents Ri, R2, R3, and R4, or said heterocyclic ring is substituted with 5 substituents R2 is oxo, (Ci-C6)alkyl, (C1-C6)alkoxy(C1-C6)alkyl, (R6)2N-(Ci-C6)alkyl, C6)alkyl, (Ci-C6)alkyl-(C=0)-NR6-(Ci-C6)alkyl, cyclo(C3-C6)alkyl, cyclo(C3-C6)alkyl(Ci-C6)alkyl, phenyl, phenyl(Ci-C6)alkyl, heterocyclyl, or heterocyclyl(Ci-C6)alkyl, wherein said phenyl, cyclo(C3-C6)alkyl, or heterocyclyl is optionally substituted with 1 or 2 substituent(s) each independenty being halogen, (d-C6)alkoxy, or (Ci-C6)alkyl-(C=0); R3 is oxo, (Ci-C6)alkyl, or phenyl; R4 is oxo or (Ci-C6)alkyl; R5 is (Ci-C6)alkyl; or two of R3; R4 and R5, both attached to the same carbon ring atom form, together with the carbon ring atom to which they are attached, a 3 membered unsubstituted carbocyclic ring; or two of Ri, R2, R3; R4 and R5 attached to the adjacent carbon ring atoms form, together with the carbon ring atoms to which they are attached, a phenyl ring, a 3 to 6 membered saturated or unsaturated carbocyclic ring, or a 5 or 6 membered saturated or unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N and S, wherein said phenyl ring, carbocyclic ring, or heterocyclic ring is unsubstituted, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 2 substituents R7 and R8; Re is H or (Ci-C6)alkyl; R7 is halogen, (Ci-C6)alkyl, (Ci-C6)alkoxy, (Ci-C6)alkyl-S-, CN, or (C C6)alkyl-(C=0)- NR6-(Ci-C6)alkyl; R8 is halogen or (Ci-C6)alkoxy; or R7 and Rg, attached to the non-adjacent carbon ring atoms, form a bridge. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following groups wherein; Z is N or O; atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following groups wherein Z is N or O, and the dotted line is a single or a double bond. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following (1) (2) (3) wherein; group (1), (2), or (3) is optionally further substituted with R2, R3, and/or R4; Z is N or O; R2 is (Ci-C6)alkyl, phenyl, or phenyl(Ci-C6)alkyl, wherein said phenyl is optionally substituted with 1 substituent being halogen or (Ci-C6)alkoxy; R3 is oxo, (Ci-C6)alkyl, or phenyl; R4 is (Ci-C6)alkyl; Re is H or (Ci-C6)alkyl; the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following (4) (5) (6) (V) wherein; group (4), (5), (6), or (7) is optionally further substituted with R3, R4, and/or R5; Z is N or O; R2 is oxo; R3 is (C C6)alkyl, (R6)2N-(C1-C6)alkyl, (R6)2N-(C=0)-(C1-C6)alkyl, cyclo(C3-C6)alkyl, cyclo(C3-C6)alkyl(Ci-C6)alkyl, phenyl, phenyl(Ci-C6)alkyl, heterocyclyl, or heterocyclyl(Ci-C6)alkyl, wherein said phenyl, cyclo(C3-C6)alkyl, or heterocyclyl is optionally substituted with 1 or 2 substituent(s) each independenty being halogen or (Ci-C6)alkyl-(C=0); R4 is oxo or (Ci-C6)alkyl; R5 is (Ci-C6)alkyl; Re is (Ci-C6)alkyl; or two of R3, R4 and R5, both attached to the same carbon ring atom form, together with the carbon ring atom to which they are attached, a 3 membered unsubstituted carbocyclic ring; and the atom marked with * is bonded to the parent molecular moiety. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following groups wherein; group (8), (9), or (10) is optionally further substituted with R4; R2 and R3 form, together with the carbon ring atoms to which they are attached, a phenyl ring or a 5 or 6 membered unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N and S, wherein said phenyl ring or heterocyclic ring is unsubstituted, or said phenyl ring or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring is substituted with 2 substituents R7 and R8; R4 is (Ci-C6)alkyl or phenyl; R7 is halogen, (C C6)alkyl, (Ci-C6)alkoxy, (C C6)alkyl-S-, CN, or (C C6)alkyl-(C=0)- H-(C1-C6)alkyl; R8 is halogen or (Ci-C6)alkoxy; the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following wherein; group (11), (12), (13), (14), or (15) is optionally further substituted with R5; R2 is oxo; R3 and R4 form, together with the carbon ring atoms to which they are attached, a phenyl ring, a 3 to 6 membered saturated or unsaturated carbocyclic ring, or a 6 membered unsaturated heterocyclic ring containing 1 ring heteroatom being N, wherein said phenyl ring, carbocyclic ring, or heterocyclic ring is unsubstituted, or said phenyl ring is substituted with 1 substituent R7, or said phenyl ring or carbocyclic ring is substituted with 2 substituents R7 and R8; R5 is phenyl; R7 is halogen or (Ci-C6)alkoxy; R8 is (Ci-C6)alkoxy; or R7 and Rg, attached to the non-adjacent carbon ring atoms, form a bridge; the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. In one embodiment the present disclosure relates to compounds of formula I, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following roups wherein; Ri and R2 form, together with the carbon ring atoms to which they are attached, a phenyl ring, or a 6 membered saturated or unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N, wherein said phenyl ring, or heterocyclic ring is unsubstituted, or said phenyl ring, or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring is substituted with 2 substituents R7 and R8; R3 is (Ci-C6)alkyl, (Ci-C6)alkoxy(Ci-C6)alkyl, or (R6)2N-(Ci-C6)alkyl; Re is H or (Ci-C6)alkyl; R7 is halogen or (Ci-C6)alkoxy; R8 is halogen; and the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. In one embodiment the present disclosure relates to compounds of formula I, wherein the compound is 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,4-dimethylpyrrolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-4,4-diphenylimidazolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidin-2-one, (3R,4R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3,4-dimethylpyrrolidine-2,5-dione, 3-((S)- 1 -(((S)-2,3-dihydrobenzo[bH^ diethyloxazolidine-2,4-dione, (R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-isopropyl-4-phenylimidazolidin-2-one, (S)- 1 -((¾)- 1 -(((S)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-isopropyl-4-phenylimidazoli one, (R)- 1 -((S)- 1 -((f5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidin-2-one, (S)- 1 -((5)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidin-2-one, 6-((S)- 1 -(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-6,7-dihydro-5H-pyrrolo[3,4-b] pyridin-5-one, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3 -yl)-2-(methylthio)-5H-pyrrolo [3 ,4-d]pyrimidin-7(6H)-one, 5 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3 ,4-d]thiazol-4-one, (R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one, (S)- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-methyl-3-phenylpyrrolidin- 1 -((5)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-ethylimidazolidin-2-one, 2-(3-((5)-l-(((Sy)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)-piperidin-3-yl)-2-oxoimidazolidin- 1 -yl)-N,N-dimethylacetamide, 5-tert-butyl-3-((S)- 1 -(((6)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)oxazolidin-2-one, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-isopropyloxazolidin-2-one, N-((3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-oxooxazolidin-5-yl)methyl)acetamide, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-(4-fluorophenyl)oxazolidin-2-one, 6-((S)- 1 -(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-(methylthio)-6,7-dihydro-5H-pyrrolo[3,4-d]pyrimidin-5-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-6,7-dihydro-5H^ 5-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-l-methyl-4,5-dihydropyrrolo[3,4-c] pyrazol-6(lH)-one, l-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3 yl)- 1 ,3-dihydrobenzo[c]isothiazole 2,2-dioxide, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)indolin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-4,6-difluoro-2-methyl- lH-benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-difluoro-2-m benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3- yl)pyrrolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methylpyrrolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-phenylpyrrolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylpyrrolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo-[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)pyrrolidine-2,5-dione, 2-((5)-1-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3a,4,7,7a-tetrahydro-lH-4 methanoisoindole- 1 ,3(2H)-dione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidine-2,5-dione, (R)- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolid dione, (S)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidine-2,5-dione, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)- 1 -phenyl-3-azabicyclo[3.1.0]hexane-2,4-dione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)p^ 1-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenyl- lH-pyrrol-2(5H)-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methyl- lH-pyrrol-2(5H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-(4-fluorophenyl)- lH-pyrrol-2(5H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methyl-3-phenyl-lH-pyrrol-2 one, 1 -((£)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-(2-methoxyphenyl)-lH-pyrrol-2(5H)-one formate, l-((5)-l-(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,4-dimethylimidazoli (R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methylimidazolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methylimidazolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-phenylimidazolidin-2-on l-(( )- 1- (((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3,4-dimethylimidazolidin-2-one, 1 -benzyl-3-((5)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin- 2- yl)methyl)piperidin-3-yl)-3,4,4-trimethylimidazolidin-2-one, 1 -((5)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperi^ hydrochloride, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)tetrahydropyrimidin-2( lH)-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2- yl)methyl)piperidin-3-yl)-3-methylteto 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methoxyisoindolin-l-one, 2-((S)-1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,5-difluoroisoindolin- 1 -one hydrochloride, 2-((S)- 1 -(((S)-2,3 -dihydrobenzo [b] [1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-4-fluoroisoindolin- 1 -one hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-5-fluoroisoindolin- 1 -one hydrochloride, 2-((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methylisoindolin-l-one formate, 5-chloro-2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)isoindolin-1 -one, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)isoindoline-1 ,3-dione, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-5-fluoroisoindoline- 1 ,3-dione, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-4-fluoroisoindoline- 1 ,3-dione hydrochloride, 4-chloro-2-((5)- 1 -(((S)-2, 3 -dihydrobenzo [b] [1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)isoindoline- 1 ,3-dione hydrochloride, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methoxyisoindoline- 1 ,3-dione, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,5-dimethoxyisoindoline- 1 ,3-dione hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-l-oxoisoindoline-5-carbonitri 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-dimethoxyisoindolin- 1 -one, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-5-methoxyisoindolin- 1 -one, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6-methoxyisoindolin- 1 -one, N-((2-((S)- 1 -(((5)-2,3-dihydrobenzo [b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)- 1 -oxoisoindolin-5 -yl)methyl)-acetamide, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)quinazoline-2,4(lH,3H)-dione, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-5 -ethyl- 1 -methyl-5-phenylimidazolidine-2,4-dione, 3-((5)- 1 -(((6)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methyl-5-phenyl-imidazolidine-2,4-dione, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-5H-pyrrolo[3,4-b]pyridine-5,7(6H)-dione, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2,3-dihydro-lH-pyrrolo[3,4-c]pyridin- 1 -one, 6-((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5H-pyrrolo[3,4-b]pyridin-7(6H)-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5H-pyrrolo[3,4-d]pyrimidin-7(6H)-on^ 5-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4H-pyrrolo[3,4-d]thiazol-6(5H)-one, 5-(( HCOOH/ACN as eluent resulting in 19.5 mg of oil. 1H NMR (400 MHz, CDC13) δ ppm 7.28 - 7.43 (m, 5H) 6.72 - 6.92 (m, 4H) 4.73 (td, 1H) 4.60 (s, 1H) 4.20 - 4.34 (m, 2H) 3.80 - 4.05 (m, 3H) 3.18 - 3.33 (m, 1H) 2.87 - 3.01 (m, 1H) 2.77 (d, 1H) 2.47 - 2.66 (m, 2H) 2.04 - 2.18 (m, 2H) 1.63 - 1.89 (m, 3H) 1.33 - 1.50 (m, 1H) 1.21 - 1.30 (m, 1H). EXAMPLE 9: (5)-l-((S)-l-(((S)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidin-2-one (S)- 1 -((S)- 1 -(((5)-2,3-Dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidin-2-one was prepared according general procedure A using (S)-4-phenyl-l-((5)-piperidin-3-yl)imidazolidin-2-one (226 mg, 0.921 mmol), (2R)- 2-(bromomethyl)-2,3-dihydro-l ,4-benzodioxin (21 1 mg, 0.921 mmol), DIPEA (0.193 ml, 1.105 mmol), K2C03 (191 mg, 1.382 mmol) and ACN (1.1 ml). The product was purified by reversed phase flash chromatography to obtain 134.9 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 7.27 - 7.45 (m, 5H) 6.77 - 6.93 (m, 4H) 4.67 - 4.79 (m, 1H) 4.59 (s, 1H) 4.22 - 4.36 (m, 2H) 3.89 - 4.09 (m, 2H) 3.73 - 3.85 (m, 1H) 3.22 - 3.35 (m, 1H) 2.95 - 3.08 (m, 1H) 2.78 (d, 1H) 2.51 - 2.72 (m, 2H) 2.02 - 2.29 (m, 2H) 1.60 -1.83 (m, 3H) 1.28 - 1.40 (m, 1H). EXAMPLE 10: 6-((S)-l-(((S)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3- yl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one Step 1: (S)-Benzyl 3-(5,7-dioxo-5H-pyrrolo[3,4-b]pyridin-6(7H)-yl)piperidine-l-carboxylate To an ice cold stirred solution of (5)-benzyl 3-aminopiperidine-l-carboxylate (1.0 g, 4.268 mmol) in toluene (10 ml) was added Et3N (0.89 ml, 6.402 mmol) and stirred at RT for 30 mins. Furo[3,4-b]pyridine-5,7-dione (764 mg, 5.122 mmol) was added to the above mixture and then heated to 1 10°C for 16 h. The reaction mixture was diluted with EtOAc (60 ml) and washed with water (2 X 30 ml). The organic layer was dried and evaporated. The crude compound was purified by column chromatography to obtain 250 mg of the product. LC-MS (ES+) [M+1] : 366.1. Step 2: (S)-Benzyl 3-(5-oxo-5H-pyrrolo[3,4-b]pyridin-6(7H)-yl)piperidine-l-carboxylate A mixture of (5)-benzyl 3-(5,7-dioxo-5H-pyrrolo[3,4-b]pyridin-6(7H)-yl)piperidine-l-carboxylate (700 mg, 1.916 mmol) and zinc dust (550 mg, 8.429 mmol) in acetic acid (14 ml) was heated at 1 10°C for 16 h. The reaction mixture was cooled to RT and filtered through a pad of celite and washed with EtOAc (15 ml). Filtrate was concentrated under reduced pressure. The residue was carefully basified with saturated aqueous NaHC03 solution and extracted with DCM (2 x 80 ml). The combined organic layer was dried and evaborated. The crude compound was purified by column chromatography to obtain 320 mg of the product. LC-MS (ES+) [M+l] : 352.2. Step 3: (S)-Benzyl 3-(5-oxo-5H-pyrrolo[3,4-b]pyridin-6(7H)-yl)piperidine-l-carboxylate (iS)-Benzyl 3-(5-oxo-5H-pyrrolo[3,4-b]pyridin-6(7H)-yl)piperidine-l-carboxylate was prepared according to the general procedure D using (5)-benzyl 3-(5-oxo-5H-pyrrolo[3,4-b]pyridin-6(7H)-yl)piperidine-l-carboxylate (600 mg, mmol), 10% Pd/C (300 mg) and EtOAc (40 ml). The crude compound was purified by triturating with Et20 to obtain 220 mg of the product. LC-MS (ES+) [M+l] : 218.2. Step 4: 6-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-6,7- dihydro-5H-pyrrolo[3,4-b]pyridin-5-one 6-((S)- 1 -(((S)-2,3-Dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one was prepared according to the general procedure A using (S)-6-(piperidin-3-yl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one (208 mg, 0.957 mmol), (R)-(2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate (310 mg, 0.968 mmol), DIPEA (0.200 ml, 1.149 mmol), K2C03 (198 mg, 1.436 mmol) and ACN (1 ml). The product was purified by reversed phase flash chromatography to obtain 68 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 1.55 - 1.68 (m, 1H) 1.70 - 1.87 (m, 2H) 1.88 - 2.02 (m, 1H) 2.20 - 2.40 (m, 2H) 2.58 - 2.77 (m, 2H) 2.79 - 2.91 (m, 1H) 3.00 - 3.13 (m, 1H) 3.97 -4.08 (m, 1H) 4.25 - 4.38 (m, 2H) 4.39 - 4.56 (m, 3H) 6.69 - 6.97 (m, 4H) 7.33 - 7.47 (m, 1H) 8.07 - 8.19 (m, 1H) 8.67 - 8.78 (m, 1H). EXAMPLE 11: 2-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-lH-pyrrolo [3,4-c] pyridin-3(2H)-one Step 1: (S)-Benzyl 3-(3-oxo-lH-pyrrolo[3,4-c]pyridin-2 3H)-yl)piperidine-l-carboxylate A mixture of (5)-benzyl 3-(l ,3-dioxo-iH-pyrrolo[3,4-c]pyridin-2(JH)-yl)piperidine-l-carboxylate (1.0 g, 2.73 mmol) and zinc dust (0.9 g, 13.68 mmol) in acetic acid (16 ml) was heated at 1 10°C for 6 h . The reaction mixture was cooled to RT and filtered through a pad of Celite and washed with EtOAc (20 ml). Filtrate was concentrated under reduced pressure. The residue was basified with saturated aqueous NaHC03 solution and extracted with DCM (2 x 80 ml). The combined organic layer was dried and evaborated. The crude compound was purified by column chromatography to obtain 800 mg of the product. LC-MS (ES+) [M+l] : 352.2. Step 2: (S)-2-(Piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one (5)-2-(Piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one was prepared according to the general procedure D using ((5)-benzyl 3-(l ,3-dioxo-lH-pyrrolo[3,4-c]pyridin-2(3H)-yl)piperidine-l-carboxylate (0.5 g, 1.42 mmol), 10% Pd/C (0.4 g) and EtOAc (20 ml). The crude compound was purified by triturating with Et20 to obtain 150 mg of the product. LC-MS (ES+) [M+l] : 218.1. Step 3: 2-((5)-l-(((S)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-lH-pyrrolo [3,4-c] pyridin-3(2H)-one 2-((S)- 1 -(((S)-2,3-Dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one was prepared according to the general procedure A using ((S)-2-(piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one (180 mg, 0.828 mmol), (R)-(2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate (265 mg, 0.828 mmol), DIPEA (0.173 ml, 0.994 mmol), K2C03 (172 mg, 1.243mmol) and ACN (1 ml). The product was purified by reversed phase flash chromatography to obtain 47 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 1.55 - 1.64 (m, IH) 1.74 - 1.84 (m, 2H) 1.86 - 1.95 (m, IH) 2.26 - 2.42 (m, 2H) 2.62 - 2.74 (m, 2H) 2.83 (dt, IH) 3.03 (dd, IH) 4.03 (dd, IH) 4.25 - 4.34 (m, 2H) 4.41 - 4.57 (m, 3H) 6.80 - 6.88 (m, 4H) 7.42 (dd, IH) 8.73 - 8.77 (m, IH) 9.10 (d, IH). EXAMPLE 12: 6-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-(methylthio)-5H-pyrrolo[3,4-d]pyrimidin-7(6H)-one Step 1: (4-Chloro-2-(methylthio)pyrimidin-5-yl)methyl methanesulfonate To a cold stirred solution of (4-chloro-2-(methylthio)pyrimidin-5-yl)methanol (4.3 g, 22.63 mmol, WO2008/094602) in DCM (45 ml) were added Et3N (7.95 ml, 56.57 mmol) and methanesulfonyl chloride (2.1 ml, 27.157 mmol) at 0°C. The resulting solution was stirred at RT for 2 h. The reaction mixture was diluted with DCM (50 ml) and washed with water (1x50 ml) brine (1x50 ml).The organic layer was dried and evaborated to obtain 3.9 g of the product. LC-MS (ES+) [M+l] : 269.0. Step 2: (S)-tert- utyl 3-(((4-chloro-2-(methylthio)pyrimidin-5-yl)methyl)amino)-piperidine-l-carboxylate To a stirred solution of (4-chloro-2-(methylthio)pyrimidin-5-yl)methyl methanesulfonate (3.9 g, 14.606 mmol) and (S)-tert-butyl 3-aminopiperidine-l-carboxylate (2.92 g, 14.606 mmol) in ACN (40 ml) was added K2C03 (5.03 g, 36.516 mmol) at RT and stirred for 16 h. The reaction was concentrated under reduced pressure. The obtained residue was dissolved in mixture of EtOAc (100 ml) and water (100 ml). The organic layer was dried and evaborated. The crude product was purified by column chromatography to obtain 2.7 g of the product. 1H NMR (400 MHz, DMSO) δ ppm 1.21-1.32 (m, 3H) 1.37 (s, 9H) 1.63 - 1.66 (m, IH) 1.85-1.99 (m, 1H) 2.28 - 2.33 (m, 1H) 2.41-2.45 (m, 1H) 2.52 (s, 3H) 2.84 - 2.90 (m, 1H) 3.02 (dd, 1H) 3.6 (bs, 1H) 3.76 (s, 2H) 8.65 (s, 1H). Step 3: (5)-tert-Butyl 3-(2-(methylthio)-7-oxo-5H-pyrrolo[3,4-d]pyrimidin-6(7H)-yl)piperidine-l-carboxylate To a solution of (S)-tert-butyl 3-(((4-chloro-2-(methylthio)pyrimidin-5-yl)methyl)amino)-piperidine-l-carboxylate (2.7 g, 7.258 mmol) in ethanol (80 ml) were added sodium acetate and PdCl2(dppf).CH2Cl2 (142 mg, 0.362 mmol) in a steel bomb. The resulting reaction mixture was subjected to carbonyl insertion with CO gas (500 psi) and heated to 140°C for 16 h. The reaction mixture was concentrated under reduced pressure. The residue was dissolved in EtOAc (100 ml), washed with water (2x100 ml) and brine (1x100 ml). The organic layer was dried and evaborated. The crude product was purified by column chromatography to obtain 1.6 g of the product. 1H NMR (400 MHz, DMSO) δ ppm 1.21-1.32 (m, 3H) 1.40 (s, 9H) 1.35 - 1.49 (m, 2H) 1.75 - 1.80 (m, 2H) 1.89 (m, 1H) 2.58 (s, 3H) 2.75 (m, 1H) 2.96 (m, 1H) 3.86-3.90 (m, 1H) 3.99-4.04 (m, 2H) 4.53 (s, 2H) 8.99 (s, 1H). Step 4: (S)-2-(Methylthio)-6-(piperidin-3-yl)-5H-pyrrolo[3,4-d]pyrimidin-7(6H)-one (S)-2-(Methylthio)-6-(piperidin^ was prepared according to the general procedure E using {S)-tert-bvXy\ 3-(2-(methylthio)-7-oxo-5H-pyrrolo[3,4-d]pyrimidin-6(7H)-yl)piperidine-l-carboxylate (400 mg, 1.098 mmol) and 1M HC1 in dioxane (25 ml). The residue was triturated with pentane to obtain 300 mg of product. LC-MS (ES+) [M+l]: 265.1. Step 5: 6-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-(methylthio)-5H-pyrrolo[3,4-d]pyrimidin-7(6H)-one 6-((5)-l-(((5)-2,3-Dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-(methylthio)-5H-pyrrolo[3,4-d]pyrimidin-7(6H)-one was prepared according to the general procedure A using ((5)-2-(piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one (310 mg, 0.968 mmol), (i?)-(2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate (265 mg, 0.968 mmol), DIPEA (0.202 ml, 1.161 mmol), K2C03 (201 mg, 1.451 mmol) and ACN (1 ml). The product was purified by reversed phase flash chromatography to obtain 99 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 1.67 - 1.96 (m, 4H) 2.24 - 2.52 (m, 2H) 2.58 - 2.74 (m, 2H) 2.66 (s, 3H) 2.77 - 2.91 (m, 1H) 3.02 (dd, 1H) 3.96 - 4.1 1 (m, 1H) 4.23 - 4.35 (m, 2H) 4.47 - 4.61 (m, 3H) 6.74 - 6.95 (m, 4H) 8.72 (s, 1H). EXAMPLE 13: 5-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3,4-d]thiazol-4-one Step 1: (S)-tert- utyl 3-(5-methylthiazole-4-carboxamido)piperidine-l-carboxylate To a stirred solution of 5-methylthiazole-4-carboxylic acid (4.0 g, 27.97 mmol, WO2008/016192) and {S)-tert-bvXy\ 3-aminopiperidine-l-carboxylate (6.15 g, 30.76 mmol) in DCM were added EDC.HC1 (6.51 g, 41.95 mmol), HOBt (6.42 g, 41.95 mmol) and DMAP (8.53 g, 69.93 mmol) at 0°C. The reaction mixture was stirred for 16 h. The reaction mixture was diluted with DCM, washed with water, brine, dried and evaborated. The crude product was purified by flash column to obtain 6.0 g of the product. LC-MS (ES+) [M+l] :326.2. Step 2: (S)-tert-Hxity\ 3-(5-(bromomethyl)thiazole-4-carboxamido)piperidine-l-carboxylate To a stirred solution of (S)-tert-butyl 3-(5-methylthiazole-4-carboxamido)piperidine-l-carboxylate (4.0 g, 12.30 mmol) in CC (80 ml) was added NBS (3.28 g, 18.46 mmol) followed by AIBN (1.61 g, 9.84 mmol) at RT. The reaction mixture was heated at 80°C for 2 h. The reaction mixture was diluted with DCM and washed with water. The combined organic layer was dried and evaborated. The crude product was purified by flash column to obtain 1.0 g of the product. LC-MS (ES+) [M+l] : 406.1. Step 3: (5)-tert-Butyl 3-(4-oxo-4H-pyrrolo[3,4-d]thiazol-5(6H)-yl)piperidine-l-carboxylate To a stirred solution of (S)-tert-butyl 3-(5-(bromomethyl)thiazole-4-carboxamido)-piperidine-1 -carboxylate (0.4 g, 0.992 mmol) in THF (10 ml) was added NaH (0.034 g, 1.48 mmol) at -10°C. The reaction mixture was stirred at -10°C to 0°C for 30 minutes. The reaction mixture was diluted with EtOAc and quenched with water. The organic layer was dried and evaborated. The crude product was purified by flash column to obtain 200 mg of the product. LC-MS (ES+) [M+l]: 324.2. Step 4: (5)-5-(Piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3,4-d]thiazol-4-one, HC1 (5)-5-(Piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3,4-d]thiazol-4-one was prepared according to the general procedure E using {S)-tert-bvXy\ 3-(4-oxo-4H-pyrrolo[3,4-d]thiazol-5(6H)-yl)piperidine-l -carboxylate (300 mgO.928 mmol) and HC1 in dioxane (10 ml). The residue was triturated with Et20- pentane to obtain 230 mg of the product. LC-MS (ES+) [M+l]: 224.1. Step 5: 5-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3,4-d]thiazol-4-one 5-((S)-l-(((¾-2,3-Dihydrobenzo[b][l,4]diox^ pyrrolo[3,4-d]thiazol-4-one was prepared according to the general procedure A using (S)-5-(piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3,4-d]thiazol-4-one hydrochloride (220 mg, 0.847 mmol), (i?)-(2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate (271 mg, 0.847 mmol), DIPEA (0.177 ml, 1.016 mmol), K2C03 (293 mg, 2.117 mmol) and ACN (1 ml). The product was purified by reversed phase flash chromatography to obtain 55 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 1.68 - 1.85 (m, 2H) 1.86 - 1.97 (m, 1H) 1.97 - 2.05 (m, 1H) 2.19 - 2.50 (m, 2H) 2.62 - 2.74 (m, 2H) 2.74 - 2.86 (m, 1H) 3.04 (dd, 1H) 3.91 - 4.08 (m, 1H) 4.23 - 4.37 (m, 2H) 4.37 - 4.50 (m, 1H) 4.52 - 4.68 (m, 2H) 6.75 - 6.94 (m, 4H) 8.89 (s, 1H). EXAMPLE 14: (R)-l-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one Step 1: (S)-Benzyl-3-((R)-3-methyl-2-oxo-3-phenylpyrrolidin-l-yl)piperidine-l-carboxylate and (S)-benzyl-3-((S)-3-methyl-2-oxo-3-phenylpyrrolidin-l-yl)piperidine-1-carboxylate To and ice cold stirred solution of methyl 2-methyl-4-oxo-2-phenylbutanoate (3.2 g, 15.51 mmol, Organic Letters, 2014, 16(1), 14) in acetic acid (65 ml) was added (S)-benzyl 3-aminopiperidine- 1-carboxylate (3.64 g, 15.51 mmol) and zinc metal (10 g, 155 mmol). The reaction mixture was stirred at 120°C for 6 h. The reaction mixture was cooled to RT and filtered through a pad of celite. Filtrate was concentrated under reduced pressure; the residue was diluted with DCM (150 ml) and washed with saturated aqueous NaHC03 (2 x 60 ml) and brine. The organic layer was dried and evaborated. The crude compound was purified by column chromatography to obtain 710 mg of (5)-benzyl 3-((i?)-3-methyl-2-oxo-3-phenylpyrrolidin-l-yl)piperidine-l-carboxylate and 700 mg of (5)-benzyl 3-((5)-3-methyl-2-oxo-3-phenylpyrrolidin- 1 -yl)piperidine- 1 -carboxylate. LC-MS (ES+) [M+l] : 393.2 for both enantiomers. Step 2: (R)-3-Methyl-3-phenyl-l-((S)-piperidin-3-yl)pyrrolidin-2-one (i?)-3-Methyl-3-phenyl-l-((5)-piperidin-3-yl)pyrrolidin-2-one was prepared according to the general procedure D using (5)-benzyl 3-((i?)-3-methyl-2-oxo-3-phenylpyrrolidin-l-yl)piperidine-l -carboxylate (760 mg, 1.94 mmol), 10% Pd/C (0.4 g) and EtOAc (80 ml). The crude compound was used without further purification. LC-MS (ES+) [M+l] : 259.3. Step 3: (R)-l-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one (R)- 1 -((S)- 1 -(((5)-2,3-Dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one was prepared according to the general procedure A using (i?)-3-methyl-3-phenyl-l-((5)-piperidin-3-yl)pyrrolidin-2-one (170 mg, 0.658 mmol), (R)-(2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate (253 mg, 0.79 mmol), K2C03 (227 mg, 1.645 mmol) and ACN (1 ml). The product was purified by reversed phase flash chromatography to obtain 136 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 1.35 - 1.48 (m, 1H) 1.53 (s, 3H) 1.63 - 1.82 (m, 3H) 2.03 - 2.27 (m, 3H) 2.41 (ddd, 1H) 2.56 - 2.71 (m, 2H) 2.74 - 2.87 (m, 1H) 2.87 - 3.02 (m, 1H) 3.15 - 3.39 (m, 2H) 4.02 (dd, 1H) 4.15 - 4.38 (m, 3H) 6.76 - 6.93 (m, 4H) 7.12 - 7.26 (m, 1H) 7.30 - 7.45 (m, 4H). EXAMPLE 15: (S)-l-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one Step 1: (S)-3-Methyl-3-phenyl-l-((S)-piperidin-3-yl)pyrrolidin-2-one (5)-3-Methyl-3-phenyl-l-((5)-piperidin-3-yl)pyrrolidin-2-one was prepared according to the general procedure D using (5)-benzyl 3-((5)-3-methyl-2-oxo-3-phenylpyrrolidin-l-yl)piperidine-l -carboxylate (740 mg, 1.89 mmol), 10% Pd/C (0.4 g) and EtOAc (80 ml). The crude compound was used without further purification. LC-MS (ES+) [M+l] : 259.3. Step 2: (5)-l-((5)-l-(((S)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one (S)- 1 -((S)- 1 -(((5)-2,3-Dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidin-2-one was prepared according to the general procedure A using (S)-3-methyl-3-phenyl-l-((5)-piperidin-3-yl)pyrrolidin-2-one (150 mg, 0.581 mmol), (R)-(2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate (223 mg, 0.697 mmol), K2C03 (201 mg, 1.45 lmmol) and ACN (1 ml). The product was purified by reversed phase flash chromatography to obtain 67 mg of the product. 1H NMR (400 MHz, CDC13) δ ppm 1.41 - 1.50 (m, 1H) 1.52 (s, 3H) 1.63 - 1.85 (m, 3H) 2.06 - 2.21 (m, 3H) 2.41 (ddd, 1H) 2.56 - 2.72 (m, 2H) 2.82 (br d, 1H) 2.88 - 2.95 (m, 1H) 3.22 (dt, 1H) 3.37 (ddd, 1H) 3.93 - 4.10 (m, 1H) 4.13 - 4.33 (m, 3H) 6.80 - 6.89 (m, 4H) 7.19 - 7.25 (m, 1H) 7.28 - 7.44 (m, 4H). EXAMPLE 16: l-((S)-l-(((S)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-ethylimidazolidin-2-one 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidin-2-one (100 mg, 0.315 mmol) was dissolved in DMF (1 ml) and cooled down to 0°C under nitrogen athmosphere and NaH (25.2 mg, 0.630 mmol) was added. After stirring the reaction mixture for 20 minutes, bromoethane (0.030 ml, 0.410 mmol) was added and the reaction mixture was stirred on an ice-bath for 4 hours and continued at room temperature over night. After completion of the reaction water was added and the reaction mixture was extracted three times with dichloromethane. The organic phase was dried and evaborated to dryness. The evaboration residue was purified by reversed phase flash chromatography followed by normal phase flash chromatography to obtain 23.9 mg of the product. 1H NMR (400 MHz, CDC13): δ ppm 6.78 - 6.89 (m, 4H) 4.22 - 4.36 (m, 2H) 3.80 - 4.06 (m, 2H) 3.17 - 3.43 (m, 6H) 2.88 - 3.01 (m, 1H) 2.75 - 2.85 (m, 1H) 2.50 - 2.71 (m, 2H) 1.94 - 2.24 (m, 2H) 1.63 - 1.83 (m, 3H) 1.31 - 1.45 (m, 1H) 1.04 - 1.17 (m, 3H). EXAMPLE 17: 2-(3-((5)-l-(((S 2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)-piperidin-3-yl)-2-oxoimidazolidin-l-yl)- V, V-dimethylacetamide 2-(3-((5)-l-(((5)-2,3-Dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)^ oxoirnidazolidin-l-yl)-N,N-dimethylacetamide was prepared as compound of Example 16 using 1 -((S)- 1 -(((iS)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidin-2-one (200 mg, 0.630 mmol) and 2-chloro-N,N-dimethylacetamide (0.084 ml, 0.819 mmol). The evaboration residue was purified by reversed phase flash chromatography followed by normal phase flash chromatography to obtain 12.3 mg of the product. 1H NMR (400 MHz, CDC13): δ ppm 6.76 - 6.92 (m, 4H) 4.17 - 4.40 (m, 2H) 3.83 - 4.07 (m, 4H) 3.30 - 3.55 (m, 4H) 2.90 - 3.05 (m, 7H) 2.75 - 2.86 (m, 1H) 2.50 - 2.73 (m, 2H) 2.02 -2.27 (m, 2H) 1.65 - 1.86 (m, 3H) 1.32 - 1.48 (m, 1H). EXAMPLE 18: 5-^-Butyl-3-((5)-l-(((S)-2,3-dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-yl)oxazolidin-2-one Step 1: l-((5)-l-(((5)-2,3-Dihydrobenzo[b] [l,4]dioxin-2-yl)methyl)piperidin-3-ylamino)-3,3-dimethylbutan-2-ol A mixture of (l , l-dimethylethyl)oxirane (4.59 mmol, 0.559 ml), (5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-amine (2.295 mmol, 0.57 g) and 2-propanol (4.2 ml) was heated at 170°C in the microwave for 2.5 hours. The solvents were evaporated. The evaboration residue was purified by reversed phase flash chromatography to obtain 595 mg of the product. CLAIMS 1. A compound of formula I, wherein; Ra and Rb form, together with the nitrogen atom to which they are attached, a 5 or 6 membered saturated or unsaturated heterocyclic ring, containing, in addition to the nitrogen atom to which Ra and Rb are attached, 0, 1 or 2 ring heteroatom(s) each independently selected from N, O and S, wherein said heterocyclic ring is substituted with 1 substituent Ri, or said heterocyclic ring is substituted with 2 substituents Ri and R2, or said heterocyclic ring is substituted with 3 substituents Ri, R2, and R3, or said heterocyclic ring is substituted with 4 substituents Ri, R2, R3, and R4, or said heterocyclic ring is substituted with 5 substituents Ri, R2, R3, R4 and R5 are independently oxo, (Ci-C6)alkyl, (Ci-C6)alkoxy(Ci-C6)alkyl, (¾6)2Ν-, (R6)2N-(C1-C6)alkyl, (R6)2N-(C=0)-(C1-C6)alkyl, (C1-C6)alkyl-(C=0)-NR6-(C1-C6)alkyl, cyclo(C3-C6)alkyl, cyclo(C3-C6)alkyl(Ci-C6)alkyl, phenyl, phenyl(Ci-C6)alkyl, heterocyclyl, or heterocyclyl(Ci-C6)alkyl, wherein said phenyl, cyclo(C3-C6)alkyl, or heterocyclyl is optionally substituted with 1 or 2 substituent(s) each independenty being halogen, (Ci-C6)alkoxy, or (Ci-C6)alkyl-(C=0); or two of R3; R4 and R5, both attached to the same carbon ring atom form, together with the carbon ring atom to which they are attached, a 3 membered unsubstituted carbocyclic ring; or two of Ri, R2, R3; R4 and R5, attached to the adjacent carbon ring atoms form, together with the carbon ring atoms to which they are attached, a phenyl ring, a 3 to 6 membered saturated or unsaturated carbocyclic ring, or a 5 or 6 membered saturated or unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N and S, wherein said phenyl ring, carbocyclic ring, or heterocyclic ring is unsubstituted, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 2 substituents R7 and R8; e is H or (Ci-C6)alkyl; R7 and R8 are independently halogen, (Ci-C6)alkyl, (Ci-C6)alkoxy, (Ci-C6)alkyl-S-, CN, or (Ci-C6)alkyl-(C=0)-NR6-(Ci-C6)alkyl; or R7 and Rg, attached to the non-adjacent carbon ring atoms, form a bridge; or a pharmaceutically acceptable salt or ester thereof. The compound according to claim 1 , wherein the compound is a compound of formula 3. The compound according to any one of claims 1 or 2, wherein; Ra and Rb form, together with the nitrogen atom to which they are attached, a 5 or 6 membered saturated or unsaturated heterocyclic ring, containing, in addition to the nitrogen atom to which Ra and Rb are attached, 0, 1 or 2 ring heteroatom(s) each independently selected from N, O and S, wherein said heterocyclic ring is substituted with 1 substituent Ri, or said heterocyclic ring is substituted with 2 substituents Ri and R2, or said heterocyclic ring is substituted with 3 substituents Ri, R2, and R3, or said heterocyclic ring is substituted with 4 substituents Ri, R2, R3, and R4, or said heterocyclic ring is substituted with 5 substituents R2 is oxo, (Ci-C6)alkyl, (C1-C6)alkoxy(C1-C6)alkyl, C6)alkyl, (Ci-C6)alkyl-(C=0)-NR6-(Ci-C6)alkyl, cyclo(C3-C6)alkyl, cyclo(C3-C6)alkyl(Ci-C6)alkyl, phenyl, phenyl(Ci-C6)alkyl, heterocyclyl, or heterocyclyl(Ci-C6)alkyl, wherein said phenyl, cyclo(C3-C6)alkyl, or heterocyclyl is optionally substituted with 1 or 2 substituent(s) each independenty being halogen, (Ci-C6)alkoxy, or (Ci-C6)alkyl-(C=0); R3 is oxo, (Ci-C6)alkyl, or phenyl; R4 is oxo or (Ci-C6)alkyl; R5 is (Ci-C6)alkyl; or two of R3; R4 and R5, both attached to the same carbon ring atom form, together with the carbon ring atom to which they are attached, a 3 membered unsubstituted carbocyclic ring; or two of Ri, R2, R3, R4 and R5 attached to the adjacent carbon ring atoms form, together with the carbon ring atoms to which they are attached, a phenyl ring, a 3 to 6 membered saturated or unsaturated carbocyclic ring, or a 5 or 6 membered saturated or unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N and S, wherein said phenyl ring, carbocyclic ring, or heterocyclic ring is unsubstituted, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring, carbocyclic ring, or heterocyclic ring is substituted with 2 substituents R7 and R8; Re is H or (Ci-C6)alkyl; R7 is halogen, (C C6)alkyl, (Ci-C6)alkoxy, (C C6)alkyl-S-, CN, or (C C6)alkyl-(C=0)-NR6-(Ci-C6)alkyl; R8 is halogen or (d-C6)alkoxy; or R7 and Rg, attached to the non-adjacent carbon ring atoms, form a bridge. 4. The compound according to any one of claims 1 to 3, wherein Ra and Rb form, together with the nitro en atom to which they are attached any one of the following groups wherein; Z is N or O; and the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. 5. The compound according to any one of claims 1 or 2, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following groups (1) (2) (3) . wherein; group (1), (2), or (3) is optionally further substituted with R2, R3, and/or R4; Z is N or O; R2 is (Ci-C6)alkyl, phenyl, or phenyl(Ci-C6)alkyl, wherein said phenyl is optionally substituted with 1 substituent being halogen or (Ci-C6)alkoxy; R3 is oxo, (Ci-C6)alkyl, or phenyl; R4 is (Ci-C6)alkyl; Re is H or (Ci-C6)alkyl; the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. 6. The compound according to any one of claims 1 or 2, wherein Ra and R, form, together with the nitrogen atom to which they are attached any one of the following groups (4) (5) (6) (V) wherein; group (4), (5), (6), or (7) is optionally further substituted with R3, R4, and/or R5; Z is N or O; R2 is oxo; R3 is (d- alkyl, (R6)2N-(C1-C6)alkyl, (R6)2N-(C=0)-(C1-C6)alkyl, cyclo(C3-C6)alkyl, cyclo(C3-C6)alkyl(Ci-C6)alkyl, phenyl, phenyl(Ci-C6)alkyl, heterocyclyl, or heterocyclyl(Ci-C6)alkyl, wherein said phenyl, cyclo(C3-C6)alkyl, or heterocyclyl is optionally substituted with 1 or 2 substituent(s) each independenty being halogen or (Ci-C6)alkyl-(C=0); R4 is oxo or (Ci-C6)alkyl; R5 is (Ci-C6)alkyl; Re is (Ci-C6)alkyl; or two of R3; R4 and R5, both attached to the same carbon ring atom form, together with the carbon ring atom to which they are attached, a 3 membered unsubstituted carbocyclic ring; and the atom marked with * is bonded to the parent molecular moiety. 7. The compound according to any one of claims 1 or 2, wherein Ra and R, form, together with the nitrogen atom to which they are attached any one of the following groups wherein; group (8), (9), or (10) is optionally further substituted with R4; R2 and R3 form, together with the carbon ring atoms to which they are attached, a phenyl ring or a 5 or 6 membered unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N and S, wherein said phenyl ring or heterocyclic ring is unsubstituted, or said phenyl ring or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring is substituted with 2 substituents R7 and R8; R4 is (Ci-C6)alkyl or phenyl; R7 is halogen, (C C6)alkyl, (Ci-C6)alkoxy, (C C6)alkyl-S-, CN, or (C C6)alkyl-(C=0)- H-(d- alkyl; R8 is halogen or (d-C6)alkoxy; the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. 8. The compound according to any one of claims 1 or 2, wherein Ra and Rb form, together with the nitrogen atom to which they are attached any one of the following groups wherein; group (11), (12), (13), (14), or (15) is optionally further substituted with R5; R2 is oxo; R3 and R4 form, together with the carbon ring atoms to which they are attached, a phenyl ring, a 3 to 6 membered saturated or unsaturated carbocyclic ring, or a 6 membered unsaturated heterocyclic ring containing 1 ring heteroatom being N, wherein said phenyl ring, carbocyclic ring, or heterocyclic ring is unsubstituted, or said phenyl ring is substituted with 1 substituent R7, or said phenyl ring or carbocyclic ring is substituted with 2 substituents R7 and R8; R5 is phenyl; R7 is halogen or (d-C6)alkoxy; R8 is (Ci-C6)alkoxy; or R7 and R8, attached to the non-adjacent carbon ring atoms, form a bridge; the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. 9. The compound according to any one of claims 1 or 2, wherein Ra and Rb form, together with the nitro en atom to which they are attached any one of the following groups wherein; Ri and R2 form, together with the carbon ring atoms to which they are attached, a phenyl ring, or a 6 membered saturated or unsaturated heterocyclic ring containing 1 or 2 ring heteroatom(s) each independently selected from N, wherein said phenyl ring, or heterocyclic ring is unsubstituted, or said phenyl ring, or heterocyclic ring is substituted with 1 substituent R7, or said phenyl ring is substituted with 2 substituents R7 and R8; R3 is (Ci-C6)alkyl, (Ci-C6)alkoxy(Ci-C6)alkyl, or (R6)2N-(Ci-C6)alkyl; Re is H or (Ci-C6)alkyl; R7 is halogen or (d-C6)alkoxy; R8 is halogen; and the atom marked with * is bonded to the parent molecular moiety, and the dotted line is a single or a double bond. 10. The compound according to claim 1, wherein the compound is l-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,4-dimethylpyrrolidin-2-one, l-(( )-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,4-diphenyl- imidazolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidin-2-one, (3R.4R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3,4-dimethylpyrrolidine-2,5-dione, 3-((5)-1-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,5-diethyloxazolidine-2,4-dio (R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-isopropyl-4-phenylimidazolidin-2-one, (S)- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-isopropyl-4-phenylimidazolidin-2-one, (R)- 1 -((S)- 1 -(( ¾ -2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylimidazolidm^ ((S)-l-(((S)-2,3-dihydrobenzo[b][l ,4]dioxm^ imidazolidin-2-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-lH-pyrrolo[3,4-c]pyridin-3(2H)-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-2-(methylthio)-5H-pyrrolo [3 ,4-d]pyrimidin-7(6H)-one, 5-((5)- 1 -(((5)-2,3-dihydrobenzo[b][ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-5,6-dihydro-4H-pyrrolo[3,4-d]thiazol-4-one, (R)- 1 -((5)- 1 -(((S)-2,3-dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-3 -methyl-3 -phenylpyrrolidin-2-one, (5)- 1 -((5)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4] dioxin-2-yl)methyl)-piperidin-3-yl)-3 -methyl-3 -phenylpyrrolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3 -yl)-3 -ethylimidazolidin-2-one, 2-(3 -((S)- 1 -(((S) -2,3 -dihydrobenzo [b] [ 1 ,4] -dioxin-2-yl)methyl)-piperidin-3-yl)-2-oxoimidazolidin- 1 -yl)-N,N-dimethylacetamide, 5-tert-butyl-3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)oxazolid 3-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-isopropyloxazolidin-2-one, N-((3-((S)- 1 -(((5)-2,3-dihydrobenzo[b][ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-2-oxooxazolidin-5-yl)methyl)acetamide, 3-((5)- 1 -(((5)-2,3-dihydrobenzo-[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3 -yl)-5 -(4-fluorophenyl)oxazolidin-2-one, 6-((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)m dihydro-5H-pyrrolo[3,4-d]pyrimidin-5-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6,7-dihydro-5H-pyrrolo[3,4-d]pyrirm 5-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-l-methyl-4,5-dihydropyTO [3,4-c]pyrazol-6(lH)-one, l-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)- 1 ,3-dihydrobenzo[c]isothiazole 2,2-dioxide, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)indolin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,6-difluoro-2-methyl-lH- benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-difluoro-2-methyl- lH-benzo[d]imidazole, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)pyrrolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-5-methylpyrrolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-3 -phenylpyrrolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)m 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)pyrrolidine-2,5-dione, 2-((S)-l-(((S)-2,3-dihydrobenzo[b][l ,4]dioxm^ tetrahydro- lH-4,7-methanoisoindole- 1 ,3(2H)-dione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo-[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidine-2,5-dion (i?)-l-((S)- 1 -(((S)-2,3 -dihydrobenzo [b] [1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-3 -methyl-3 -phenylpyrrolidine-2,5-dione, (S)- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-3-phenylpyrrolidine-2,5-dione, 3-((5)- 1 -(((S)-2,3-dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)- 1 -phenyl-3 -azabicyclo[3.1.0]-hexane-2,4-dione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenylpyrrolidine-2,3-dione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-phenyl- lH-pyrrol-2(5H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo-[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methyl- lH-pyrrol-2(5H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-(4-fluorophenyl)-lH-pyrroi^ 2(5H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methyl-3-phenyl- lH-pyrrol-2(5H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-(2-methoxyphenyl)- lH-pyrrol-2(5H)-one formate, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidm^ (((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)meth^ 2- one, (R)- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-4-methylimidazolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methylimidazolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo-[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-phenylimidazolidin-2-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo [b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3 ,4-dimethylimidazolidin-2-one, 1 -benzyl-3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin- 3- yl)-3,4,4-trimethylimidazolidin-2-one, l-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3 -yl)-3 -( 1 -phenylethyl)imidazolidin-2-one hydrochloride, 1 -((S)- 1 -(((6)- 2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)tetrahydropyrim 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methyl-tetrahydropyrimidin-2(lH)-one, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methoxyisoindolin- 1 -one, 2-((S)- 1 -(((S)-2,3-dihydrobenzo- [b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,5-difluoroisoindolin-l-one hydrochloride, 2- ((S)-l-(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-^^^ 1 -one hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-fluoroisoindolin- 1 -one hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-5-methylisoindolin- 1 -one formate, 5-chloro-2-((5)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)isoindolin- 1 -one, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)isoindoline- 1 ,3-dione, 2-((S)- 1 -(((6)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)meth^ 2-((S)-l-(((S)-2,3-dihydrobenzo[b][l ,4]dioxm^ 1 ,3-dione hydrochloride, 4-chloro-2-((5)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)isoindoline- 1 ,3-dione hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-methoxy-isoindoline-l ,3-dione, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4,5-dimethoxyisoindoline- 1 ,3-dione hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo-[b] [ 1 ,4]dioxin-2-yl)methyl)piperidin-3 -yl)- 1 -oxoisoindoline-5 -carbonitrile, 2-((S)- 1 -(((6)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,6-dimethoxyisoindolin-l-one, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methoxyisoindolin- 1 -one, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-6-methoxyisoindolin- 1 -one, N-((2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)- 1 -oxoisoindolin-5-yl)methyl)acetamide, 3-((5)- 1 -(((5)-2,3 dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)quinazoline-2,4(lH,3H)-dione, 3-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-5-ethyl- 1 -methyl-5-phenylimidazolidine-2,4-dione, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methyl-5-phenylimidazolidine-2,4-dione, 6-((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5H-pyrrolo[3,4-b]pyridine-5,7(6H)-dione, 2-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2,3-dihydro- lH-pyrrolo[3,4-c]pyridin- 1 -one, 6-((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5H-pyrrolo[3,4-b]pyridin-7(6H)-one, 6-((5)-l-(((5)-2,3-dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-5H-pyrrolo [3 ,4-d]pyrirnidin-7(6H)- one, 5-((S)- 1 -(((S)-2,3 -dihydrobenzo [b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-4H-pyrrolo-[3,4-d]thiazol-6(5H)-one, 5-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-l-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(lH)-one, 2-((5)-l-(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2,3-dihydrobenzo[d]isothiazole- 1 , 1-dioxide, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6-fluoro-lH-benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6-fluoro-2-methyl- lH-benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-ethyl-6-fluoro-lH-benzo[d]-imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6-fluoro-2-isopropyl- lH-benzo[d]imidazole, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-6-fluoro- lH-benzo[d]imidazol-2(3H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-fluoro-lH-benzo[d]imidazole, 1-((S)- 1 -(((S)-2,3-dihydrobenzo[b][ 1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-fluoro- 1H-benzo[d]imidazol-2(3H)-one, 6-chloro- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- lH-benzo[d]imidazole, 6-chloro- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo-[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-methyl- lH-benzo[d]imidazole, 5-chloro- 1 -((S)- 1- (((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-lH-benzo[d]-im^ 2- ((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)tetrahydrocyclopenta[c]pyrrole- 1 ,3(2H,3aH)-dione hydrochloride, (3aR,7aS)-2-((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)hexahydro-lH-isoindole-1 ,3(2H)-dione hydrochloride, 2-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-4,5,6,7-tetrahydro- lH-isoindole- 1 ,3(2H)-dione hydrochloride, 3-((5)- 1 -(((6)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-azabicyclo[3.1.0]hexane-2,4-dione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-ethylpyrimidine-2,4,6( lH,3H,5H)-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [ 1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-methylpyrrolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo-[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methylpyrrolidin-2-one diastereomer 1 , l-((5)-l-(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)m diastereomer 2, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3,3-dimethylpyrrolidin-2-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methylimidazolidin-2-one, 3-((5)- 1 -(((5)-2,3-dihydrobenzo-[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4-dione, 3-((5)-1-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-l-methylimidazolidine-2,4-di 3- ((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- 1 -isopropyl-imidazolidine-2,4-dione, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)-piperidin-3-yl)- 1 -ethylimidazolidine-2,4-dione, 1 -cyclopentyl-3-((5)- 1 -(((S)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4-di 3-(( -l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)m 2,4-dione, 1 -(cyclopropylmethyl)-3-((5)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4-dione, 2-(3-((S)- 1 -(((5)-2,3-dihydrobenzo-[b][l,4]dioxin-2-yl)methyl)piperidin-3^ acetamide, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,5-dimethylimidazolidine-2,4-dione, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-l,5,5-trimethylimidazolidine-2,4 (i?)-3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methylimidazolidm^ (S)-3-((S)-l-(((S)-2,3-dihydrobenzo[b]^ imidazolidine-2,4-dione, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)-piperidin-3 -yl)-5 -phenylimidazolidine-2,4-dione, 3 -((S)- 1 -(((S)-2,3 -dihydrobenzo [b] [ 1 ,4] -dioxin-2-yl)methyl)-piperidin-3-yl)- 1 ,5-dimethylimidazolidine-2,4-dione, 3-((5)- 1 -(((S)-2,3-dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)-piperidin-3 -yl)- 1 -isopropyl-5 ,5 -dimethyl-imidazolidine-2,4-dione, 1 -tert-butyl-3-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4-dione, 1 -benzyl-3-((5)- 1 -(((5)-2,3-dihydrobenzo-[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4-dione, 1 -cyclopropyl-3-((5)- 1 -(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)m 3-((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)- 1 -(oxetan-3-yl)imidazolidine-2,4-dione, l-(3,3-difluorocyclobutyl)-3-((5)-l-(((5)-2,3-dihydrobenzo-[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4-dione, 6-((S)-l-(((S)-2,3-di ydrobenzo[b][l,4]dioxin-2-yl)methyl)-piperidin-3-yl)-4,6-diazaspiroP dione, 6-((5)-l-(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)-piperidin-3-yl)-4-me 4,6-diazaspiro[2.4]heptane-5,7-dione, 2-(6-((S)-l-(((S)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)-5,7-dioxo-4,6-dm^ 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-ethylimidazolidine-2,4,5-trione, 1 -cyclohexyl-3-((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4,5-trione, 1 -cyclopentyl-3-((5)- 1 -(((5)-2,3-dihydrobenzo[b][l,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4,5 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-((i?)- 1 - phenylethyl)imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-phenylimidazolidine-2,4,5-trione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-isopropylimidazolidm^ trione, 1 -benzyl-3-((5)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-propylimidazolidine-2,4,5-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)-piperidin-3-yl)-3-((5)- 1 -phenylethyl)imidazolidine-2,4,5-trione, 1 -tert-butyl-3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-^ yl)imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-(2-(dimethylamino)em^ 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-(tetrahydro-2H-pyran-4-yl)imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-(piperidin-4-yl)imidazolidine-2,4,5-trione dihydrochloride, 1 -((S)- 1 -(((6)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-methylimidazoM trione, 1 -(1 -acetylpiperidin-4-yl)-3-((5)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)-methyl)piperidin-3-yl)imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]-dioxin-2-yl)methyl)piperidin-3-yl)-3-(pyridin-4-ylmethyl)imidazol 1 -((S)- 1 - (((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)m 2,4,5-trione, 1 -((£)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3-(pyridin-2-ylmethyl)imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo [b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-3 -(pyridin-3 -ylmethyl)-imidazolidine-2,4,5-trione, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- 1H-benzo[d]imidazol-2(3H)-one, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo-[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- lH-benzo[d] [ 1 ,2,3]triazole, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- 1 ,3-dihydrobenzo[c][ 1 ,2,5]-thiadiazole-2,2-dioxide, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-3 -methyl- lH-benzo[d]imidazol-2(3H)-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo-[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- lH-benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-3-phenyl-lH-benzo[d]imidazol-2(3H)-one, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-methyl- lH-benzo[d]imidazole, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-2-(methoxymethyl)- lH-benzo[d]imidazole, 1 -(6-chloro- 1 -((S)- 1 -(((5)-2,3-dihydrobenzo [b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)- lH-benzo [d]imidazol-2-yl)-N,N- dimethylmethanamine, 1 -(6-chloro- 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)- lH-benzo[d]imidazol-2-yl)-N-methylmethanamine, 1 -((S)- 1 -(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-4-fluoro-lH-benzo[d]imidazol^ 2(3H)-one, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-5-methoxy-2-methyl-3H-imidazo[4,5-b]pyridine, 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]-dioxin-2-yl)methyl)-piperidin-3-yl)-2-methyl-3H-imidazo[4,5-b]pyridine, l-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)-piperidin-3-yl)-2-methyl-lH-imidazo[4,5-b]-pyridine, 1 -((S)- 1 -(((5)-2,3-dihydrobenzo[b] [1 ,4]dioxin-2-yl)methyl)piperidin-3-yl)-2-methyl-lH-imidazo[4,5-c]pyridine, 3-((S)-l-(((S)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)-methyl)piperidin-3-yl)-2-ethyl-3H-imidazo[4,5-b]pyridine, 9-((S)-l-(((S)-2,3-dihydrobenzo-[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)-8-methyl-9H-purine, 9-((S)-l-(((S)-2,3-dihydrobenzo [b] [ 1 ,4] dioxin-2-yl)methyl)-piperidin-3 -yl)-9H-purine, 2-((S)- 1 -(((S)-2,3 -dihydrobenzo[b] [ 1 ,4] dioxin-2-yl)methyl)piperidin-3 -yl)-5 ,5 -dimethylisothiazolidine- 1 , 1-dioxide, or 3-((5)-l-(((5)-2,3-dihydrobenzo[b][l ,4]dioxin-2-yl)methyl)piperidin-3-yl)oxazolidine-2,4-dione. 1 1. The compound according to any one of claims 1 to 10 for use as a medicament. 12. The compound according to any one of claims 1 to 10 for use in the treatment of a disorder, condition, or disease where an alpha2C antagonist is indicated to be useful. 13. The compound according to claim 12, wherein the disorder, condition, or disease is a mental disorder propagated by stress, Parkinson's disease, depression, schizophrenia, attention deficit hyperactivity disorder, post-traumatic stress disorder, obsessive compulsive disorder, Tourette's syndrome, blepharospasm or other focal dystonias, temporal lobe epilepsy with psychosis, a drug-induced psychosis, Huntington's disease, a disorder caused by fluctuation of the levels of sex hormones, panic disorder, Alzheimer's disease, or mild cognitive impairment. 14. A method for the treatment of a disorder, condition, or disease where an alpha2C antagonist is indicated to be useful, which method comprises administering to a mammal in need of such treatment an effective amount of at least one compound according to claim 1. 15. The method according to claim 14, wherein the disorder, condition, or disease is a mental disorder propagated by stress, Parkinson's disease, depression, schizophrenia, attention deficit hyperactivity disorder, post-traumatic stress disorder, obsessive compulsive disorder, Tourette's syndrome, blepharospasm or other focal dystonias, temporal lobe epilepsy with psychosis, a drug-induced psychosis, Huntington's disease, a disorder caused by fluctuation of the levels of sex hormones, panic disorder, Alzheimer's disease, or mild cognitive impairment. 16. A pharmaceutical composition comprising at least one compound according to any one of claims 1 to 10 and a pharmaceutically acceptable carrier, diluent, and/or excipient. 17. The pharmaceutical composition according to claim 16 wherein the composition comprises further at least one other active ingredient.