This invention relates to amino-imidazolones for the inhibition of p-secretase FIELD OF THE INVENTION This invention relates to amino-imidazolones, derivatives thereof and methods for the use thereof to preferably inhibit p-secretase (BACE) and to treat P-amyloid deposits and neurofibrillary tangles. BACKGROUND OF THE INVENTION Alzheimer's disease (AD), a progressive degenerative disease of the brain primarily associated with aging, has become a more serious healthcare problem since its initial description almost a century ago (Alzheimer, A. Centralblatt fur Nervenheikunde und Psychiatrie, 1907, 30, 117-179). For example, the number of prevalent cases of AD continues to grow at an alarming rate of more than 5% annually in Japan (Citron, M. J. Neuroscience Research, 2002, 70, 373-379). Clinically, AD is presented by characterization of loss of memory, cognition, reasoning, judgment, and orientation. Motor, sensory, and linguistic abilities are also affected as the disease progresses until global impairment of multiple cognitive functions occurs. These cognitive losses take place gradually, but typically lead to severe impairment and eventual death in 4-12 years. Consequently, there is an urgent need for pharmaceutical agents capable of halting, preventing or reversing the progression of Alzheimer's disease. β-Amyloid plaques (predominately an aggregate of a peptide fragment known as AP) and neurofibrillary tangles are two major pathologic characterizations associated with Alzheimer's disease. Patients with AD display characteristic p-amyloid deposits (P-amyloid plaques) in the brain and in cerebral blood vessels (p-amyloid angiopathy) as well as neurofibrillary tangles. Amyloidogenic plaques and vascular amyloid angiopathy also characterize the brains of patients with Trisomy 21 (Down's Syndrome), Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-type (HCHWA-D), and other neurodegenerative disorders. Neurofibrillary tangles also occur in other dementia-inducing disorders (Varghese, J., et al, Journal of Medicinal Chemistry, 2003, 46, 4625-4630). p-amyloid deposits are predominately an aggregate of Ap peptide, which in turn is a product of the proteolysis of amyloid precursor protein (APP). More specifically, Ap peptide results from the cleavage of APP at the C-terminus by one or more p-secretases, and at the N-terminus by p-secretase enzyme (BACE), also known as aspartyl prclease, as part of the β-amyloidogenic pathway. BACE activity is correlated directly to the generation of Ap peptide from APP (Sinha, et al., Nature, 1999, 402:537-540), and studies increasingly indicate that the inhibition of BACE inhibits the production of Ap peptide (Roberds, S. L., et al, Human Molecular Genetics, 2001, 10, 1317-1324). Thus, based on the foregoing, it is clear that BACE inhibitors are useful, and development of new BACE inhibitors is highly desirable. SUMMARY OF THE INVENTION The present invention provides a compound of formula I (Formula Removed) wherein R1and R2 are each independently H or an optionally substituted C1-C4alkyl group; R3 and R4 are each independently H, or an optionally substituted C1-C4alkyl group or R3 and R4 may be taken together to form a 4- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; R5, R6 and R7 are each independently H, halogen, NO2, CN, OR11, NR12R13 or a C1-C6alkyl, d-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl C3-C8cycloalkyl, cycloheteroalkyl, aryl or arylC1-C4alkyl group each optionally substituted or when attached to adjacent carbon atoms R5 and R6 may be taken together with the atoms to which they are attached to form an optionally substituted 5- to 7-membered ring optionally containing one or two heteroatoms selacted from O, N or S; R8, R9 and R10 are each independently H, halogen, NO2, CN, OR14, NRi5Ri6 or a C1-C4alkyl, C1-C4haloalkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C8cycloalkyl, cycloheteroalkyl, aryl or aryl(C1-C4)alkyl group each optionally substituted or when attached to adjacent carbon atoms R8 and R9 may be taken together with the atoms to which they are attached to form an optionally substituted 5- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; n is 0, 1 or 2; R11 and R14 are each independently H or a C1-C6alkylF C1-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C8cycloalkyl or aryl group each optionally substituted; and R12, R13, R15 and R16 are each independently H, C1-C4alkyl, C3-C8cycloalkyl or R12 and R13 or R15 or R16 may be taken together with the atom to which they are attached to form a 5- to 7-membered ring optionally containing an additional heteroatom selected from O, N or S; or a tautomer thereof, a stereoisomer thereof or a pharmaceutically acceptable salt thereof. The present invention also provides a pharmaceutical composition and methods for the treatment of β-amyloid deposits and neurofibrillary tangles. Compounds and compositions of the invention are particularly useful in treating Alzheimer's disease, cognitive impairment, Down's Syndrome, HCHWA-D, cognitive decline, senile dementia, cerebral amyloid angiopathy, degenerative dementia, or other neurodegenerative disorders. DETAILED DESCRIPTION OF THE INVENTION Alzheimer's disease (AD) is a major degenerative disease of the brain which presents clinically by progressive loss of memory, cognition, reasoning, judgement and emotional stability and gradually leads to profound mental deteoriation and death. The exact cause of AD is unknown, but increasing evidence indicates that amyloid beta peptide (A-beta) plays a central role in the pathogenesis of the disease. (D. B. Schenk; R. E. Rydel et al, Journal of Medicinal Chemistry, 1995. 21,4141 and D. J. Selkoe, Physiology Review, 2001. 81, 741). Patients with AD exhibit characteristic neuropathological markers such as neuritic plaques (and in (β-amyloid angiopathy, deposits in cerebral blood vessels) as well as neurofibrillary tangles detected in the brain at autopsy. A-beta is a major component of neuritic plaques in AD brains. In addition, β-amyloid deposits and vascular p-amyloid angiopathy also characterize individuals with Downs Syndrome, Hereditary Cerebral Hemmorhage with Amyloidosis of the Dutch type (HCHWA-D) and other neurodegenreative and dementia-inducing disorders. Over expression of the amyloid precursor protein (APP), altered cleavage of APP to A-beta or a decrease in the clearance of A-beta from a patient's brain may increase the levels of soluble or fibrullar forms of A-beta in the brain. The p-site APP cleaving enzyme, BACE1, also called memapsin-2 or Asp-2, was identified in 1999 (R. Vassar, B. D. Bennett, et al, Nature, 1999. 402, 537). BACE1 is a membrane-bound aspartic protease with all the known functional properties and characteristics of p-secretase. Parallel to BACE1, a second homologous aspartyl protease named BACE2 was found to have p-secretase activity in vitro. Low molecular weight, non-peptide, non-substrate-related inhibitors of BACE1 or p-secretase are earnestly sought both as an aid in the study of the p-secretase enzyme and as potential therapeutic agents. Surprisingly, it has now been found that amino-imidazolone compounds of formula I demonstrate inhibition of p-secretase and the selective inhibition of BACE1. Advantageously, said amino-imidazolone compounds may be used as effective therapeutic agents for the treatment, prevention or amelioration of a disease or disorder characterized by elevated p-amyloid deposits or p-amyloid levels in a patient. Accordingly, the present invention provides an amino-imidazolone compound of formula (Formula Removed) wherein R1 and R2 are each independently H or an optionally substituted C1-C4alkyl group; R3 and R4 are each independently H, or an optionally substituted C1-C4 alkyl group or R3 and R4 may be taken together to form a 4- to 7-membered ring optionally containing one or two heteroatoms selectee from O, N or S; R5, R6 and R7 are each independently H, halogen, NO2, CN, ORn, NR12R13 or a C1-C6alkyl, CrCehaloalkyl, C2-C6alkenyl, C2-C6alkynyl C3-C8cycloalkyl, cycloheteroalkyl, aryl or aryl(d-C4)alkyl group each optionally substituted or when attached to adjacent carbon atoms R5 and R6 may be taken together with the atoms to which they are attached to form an optionally substituted 5- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; R8, R9 and R10 are each independently H, halogen, NO2, CN, ORi4> NR15R16 or a C1-C6alkyl, C1-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C8cycloalkyl, cycloheteroalkyl, aryl or aryl(C1-C4)alkyl group each optionally substituted or when attached to adjacent carbon atoms R8 and R9 may be taken together with the atoms to which they are attached to form an optionally substituted 5- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; n isO, 1 or 2; RH and R14 are each independently H or a C1-C6alkyl, C1-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C8cycloalkyl or aryl group each optionally substituted; and Ri2, Ria, RIS and R16 are each independently H, C1-C4alkyl, C3-C8cycloalkyl or R12 and R13 or R15 or R16 may be taken together with the atom to which they are attached to form a 5- to 7-membered ring optionally containing an additional heteroatom selected from O, N or S; or a tautomer thereof, a stereoisomer thereof or a pharmaceutically acceptable salt thereof. As used in the specification and claims, the term halogen designates F, Cl, Br or I and the term cycloheteroalkyl designates a five- to seven-membered cycloalkyl ring system containing 1 or 2 heteroatoms, which may be the same or different, selected from N, O or S , optionally containing one double bond and the nitrogen being optionally substituted. Exemplary of the cycloheteroalkyl ring systems included in the term as designated herein are the following rings wherein X1 is NR, O or S; and R is H or an optional substituent as described hereinbelow: (Formula Removed) Similarly, as used in the specification and claims, the term aryl designates a carbocyclic aromatic ring system e.g., of 6-14 carbon atoms such as phenyl, naphthyl, anthracenyl or the like. The term aryl(C1-C4)alkyl designates an aryl group as defined hereinabove attached to a (C1-C4)alkyl group which may be straight or branched. Said aryl(C1-C4)alkyl groups include benzyl, phenethyl, naphthylmethyl, or the like, preferably benzyl. The term haloalkyl as used herein designates a CnH2n+1 group having from one to 2n+1 halogen atoms which may be the same or different and the term haloalkoxy as used herein designates an OCnH2n+1 group having from one to 2n+1 halogen atoms which may be the same or different. Preferably the term haloalkyl designates CF3 and the term haloalkoxy designates OCF3. In the specification and claims, when the terms (C1-C6)alkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C7cycloalkyl, cycloheteroalkyi, aryl or aryl(C1-C4)alkyl are designated as being optionally substituted, the substituents which are optionally present may be one or more of those customarily employed in the development of pharmaceutical compounds or the modification of such compounds to influence their structure/activity, persistence, absorption, stability or other beneficial property. Specific examples of such substituents include halogen atoms, nitro, cyano, thiocyanato, cyanato, hydroxyl, alkyl, haloalkyl, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, formyl, alkoxycarbonyl, carboxyl, alkylcarbonyl, alkylthio, alkylsuphinyl, alkylsulphonyl, carbamoyl, alkylamido, phenyl, phenoxy, benzyl, benzyloxy, heterocyclyl (e.g., cycloheteroalkyi or an aromatic heteroaryl of 5-10 ring atoms including 1-3 heteroatoms selected from O, N and S) or cycloalkyl (eg of 3-8 carbon atoms) groups, preferably halogen atoms or lower alkyl or lower alkoxy groups. Typically, 0-3 substituents may be present. When any of the foregoing substituents represents or contains an alkyl substituent group, this may be linear or branched and may contain up to 12, preferably up to 6, more preferably up to 4 carbon atoms. Typical substituents include halogen (such as fluorine), alkyl (such as methyl, ethyl, propyl and t-butyl), alkoxy (such as methoxy, ethoxy and propoxy). Pharmaceutically acceptable salts may be any acid addition salt formed by a compound of formula I and a pharmaceutically acceptable acid such as phosphoric, sulfuric, hydrochloric, hydrobromic, citric, maleic, malonic, mandelic, succinic, fumaric, acetic, lactic, nitric, sulfonic, p-toluene sulfonic, methane sulfonic acid or the like. Compounds of the invention include esters, carbamates or other conventional prodrug forms, which in general, are functio al derivatives of the compounds of the invention and which are readily converted to the inventive active moiety in vivo. Correspondingly, the method of the invention embraces the treatment of the various conditions described hereinabove with a compound of formula I or with a compound which is not specifically disclosed but which, upon administration, converts to a compound of formula I in vivo. Also included are metabolites of the compounds of the present invention defined as active species produced upon introduction of these compounds into a biological system. Compounds of the invention may exist as one or more tautomers. One skilled in the art will recognize that compounds of formula I may also exist as the tautomer (It) as shown below. (Formula Removed) Tautomers often exist in equilibrium with each other. As these tautomers interconvert under environmental and physiological conditions, they provide the same useful biological effects. The present invention includes mixtures of such tautomers as well as the individual tautomers of Formula I and Formula It. The compounds of the invention may contain one or more asymmetric carbon atoms or one or more asymmetric (chiral) centers and may thus give rise to optical isomers and diastereomers. Thus, the invention includes such optical isomers and disastereomers; as well as the racemic and resolved, enantiomerically pure stereoisomers; as well as other mixtures of the R and S stereoisomers. One skilled in the art will appreciate that one stereoisomer may be more active or may exhibit beneficial effects when enriched relative to the other stereoisomer(s) or when separated from the other stereoisomer(s). Additionally, the skilled artisan knows how to separate, enrich or selectively prepare said stereoisomers. Accordingly, the present invention comprises compounds of Formula I, the stereoisomers thereof, the tautomers thereof and the pharmaceutically acceptable salts thereof. The compounds of the invention may be present as a m -1,4,5,6-tetrahydropyrimidine Using essentially the same procedure described in Example 1, step e, and employing 3-(4-methoxybenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethanol afforded 2-{chloro[3-(4-methoxybenzyl)phenyl]phenylmethyl}-1,4,5,6- tetrahydropyrimidine as a light brown solid (1.65 g, 81% yield, m.p. 125°C). MS m/e (M+H)+405.1; 1H NMR (400 MHZ, DMSOd6) 5 1.90 (m, 2H), 3.44 (bs, 4H), 3.71 (s, 3H), 3.92 (s, 2H), 6.85 (dd, 2H), 7.12 (d, 2H), 7.17 (m, 1H), 7.23 (m, 1H), 7.34 (m, 3H), 7.41 (t, 1H), 7.49 (m, 3H), 9.44 (s, 1H). Step d) [3-(4-Methoxybenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethylamine Using essentially the same procedure described in Example, 1 step f and employing 2-{chloro[3-(4-methoxybenzyl)phenyl]phenylmethyl}-1,4,5,6- tetrahydropyrimidine, gave [3-(4-methoxybenzyl)phenyl](phenyl)1,4,5,6- tetrahydropyrimidin-2-ylmethylamine as a brown thick oil (1.55 g, 98% yield). MS m/e (M+H)+386.7; 1H NMR (400 MHZ, DMSOd6) δ 1.52 (m, 2H), 3.12 (m, 4H), 3.27 (bs, 3H), 3.66 (s, 3H), 3.77 (s, 2H), 6.79 (d, 2H), 7.06 (m, 1H), 7.08 (d, 2H), 7.22 (m, 8H). Step e) 8-[3-(4-Methoxybenzyl)phenyl]-8-phenyl-2,3,4,8-tetrahydroimidazo [1,5-a]pyrimidin-6-amine Using essentially the same procedure described in Example, 1, step g, and employing [3-(4-methoxybenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2- ylmethylamine and purifying by flash chromatography on silica gel (CH2Cl2/EtOAc/MeOH/Et3N, 2/2/5.9/0.1), the title product is obtained as a white solid (0.13 g, 8% yield, mp 132°C); MS m/e (M+H)*411; 1H NMR (400 MHZ, DMSOd6) 8 1.66 (m, 2H), 3.36 (m, 2H), 3.51 (m, 2H), 3.69 (s, 3H), 3.79 (s, 2H), 6.30 (bs, 2H), 6.81 (d, 2H), 6.97 (d, 1H), 7.14 (d, 2H), 7.16 (q, 2H), 7.22 (m, 2H), 7.30 (md, 1H), 7.38 (m, 1H), 7.44 (d, 2H). EXAMPLE 5 Preparation of 8-[3-(4-Fluorobenzvl)phenvl1-8-phenvl-2.3.4.8-tetrahvdroimidazo M .5-a]pyrimidin-6-amine Step a) 1 -Bromo-3-(4-fluorobenzyl)benzene Using essentially the same procedure described in Example 2, step a, and employing (3-bromophenyl)(4-fluorophenyl)methanone and purifying by flash chromatography on silica gel (hexane/EtOAC 95/5), 1-bromo-3-(4-fluorobenzyl)-benzene is obtained as a colorless oil (15.2 g, 80:/o yield). MS m/e (M)+ 266; 1H NMR (400 MHZ, DMSOd6) δ3.92 (s, 2H,), 7.08 (m, 2H), 7.23 (m, 4H), 7.36 (m, 1H), 7.43 (bs, 1H). Step b) [3-(4-Fluorobenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethanol Using essentially the same procedure described in Example 1, step d, and employing 1-bromo[3-(4-fluorobenzyl)phenyl]magnesium and purifying by flash chromatography on silica gel (CH2CI2/EtOAc/IPA/Et3N 3.9/2/4/0.1) and then by crystallization from isopropanol, [3-(4-fluorobenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethanol is obtained as a white solid (2.2 g, 77% yield, mp 60°C). MS m/e (M+H)+ 375.2; 1H NMR (400 MHZ, DMSOd6) δ 1.62 (m, 2H), 3.23 (bs, 4H), 3.90 (s, 2H), 6.80 (bs, 2H), 7.09 (m, 4H), 7.20 (m, 4H), 7.29 (m, 5H). Step c) 2-{Chloro[3-(4-fluorobenzyl)phenyl]phenylmethyl}-1,4,5,6-tetrahydropyrimidine Using essentially the same procedure as described in Example 1, step e, and employing [3-(4-fluorobenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethanol, 2-{chloro[3-(4-fluorobenzyl)phenyl]phenylmethyl}-1,4,5,6-tetrahydropyrimidine is obtained as a light yellow solid (2.2 g, 98% yield, mp 74°C). MS m/e (M+H)+ 393.1; 1H NMR (400 MHZ, DMSOd6) δ 1.89 (m, 2H), 3.40 (m, 4H), 3.94 (s, 2H), 7.05 (m, 2H), 7.19 (m, 4H), 7.21 (m, 3H), 7.38 (t, 1H), 7.45 (m, 3H), 9.40 (s, 1H). Step d) [[3-(4-Fluorobenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethyljamine. Using essentially the same procedure as described in Example 1, step f, and employing 2-{chloro[3-(4-fluorobenzyl)phenyl]phenylmethyl}-1,4,5,6- tetrahydropyrimidine, a residue was obtained. Purification of the residue by flash chromatography on silica gel (CH2Cl2/EtOAc/IPA/Et3N 1.9/2/6/0.1) gave [[3-(4-fluorobenzyl)phenyl]- (phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethyl]amine as a thick yellow oil (1.35 g, 64% yield). MS m/e (M+H)+ 374.2; 1H NMR (400 MHZ, DMSOd6) δ 1.53 (m, 2H), 2.65 (bs, 2H), 3.17 (m, 4H), 3.87 (s, 2H), 6.0 (bs, 1H), 7.0-7.25 (m, 13H). Step e) 8-[3-(4-Fluorobenzyl)phenyl]-8-phenyl-2,3,4,8-tetrahydroimidazo [1,5-a]pyrimidin-6-amine. Using essentially the same procedure as described in Example 1, step g, and employing [[3-(4-fluorobenzyl)phenyl](phenyl)1,4,5,6-tetrahydropyrimidin-2-ylmethyljamine, a residue was obtained. Purification of the residue by flash chromatography on silica gel (CH2Cl2/EtOAc/MeOH/Et3N, 2/2/5.9/0.1) gave 8-[3-(4- fluorobenzyl)phenyl]-8-phenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine as a white solid (0.30 g, 21 % yield mp 152 °C); MS m/e (M+H)+399; 1H NMR (400 MHZ, DMSOd6) δ 1.66 (m, 2H), 3.35 (m, 2H), 3.52 (m, 2H), 3.86 (s, 2H), 6.50 (bs, 2H), 6.99 (d, 1H), 7.07 (m, 2H), 7.17 (m, 4H), 7.22 (m, 2H), 7.23 (m, 1H), 7.36 (m, 1H), 7.43 (d, 2H). EXAMPLE 6 Preparation of 8-Phenvl-8-r3-(trifluoromethvl)phenvn-2.3.4.8-tetrahydroimidazo [1.5-alpvrimidin-6-amine Step a) 3-Trifluromethylphenylmagnesium bromide Into a solution containing 3-bromo-trifluromethylbenzene (15 g, 65, mmol) and THF (50 mL) was added magnesium metal (1.6 g, 66 mmol). The reaction was heated to reflux 18 hours. Then cooled to room temperature and used immediately. Step b) Phenyl-(1,4,5,6-tetrahydro-pyrimidin-2-yl)-3-trifluromethyl-phenyl)-methanol Into the above-prepared Gringnard solution was added Cul (0.8 g, 4.4 mmol) at room temperature followed by 2-(4,5,6-tetrahydropyrimidyl) phenyl ketone, (5 g, 26.5 mmol). The reaction was heated to reflux for 18 h and concentrated in vacuo. The resultant residue was taken in 1N HCI, washed with ether, basified with solid NaHCO3 and extracted with ethyl acetate. The organic extracts were combined, dried over MgSO4 and concentrated to dryness to afford phenyl-(1,4,5,6-tetrahydro-pyrimidin-2-yl)-3-trifluromethyl-phenyl)-methanol as an off white solid (5g, 57% yield). MS m/e 255 (M)+; 1HNMR (DMSO-d6, 300 MHz) δ 1.75 (m, 2H), 3.3 (m, 4H), 7.4 (m, 5H), 7.65 (m, 4H). Step c) 2-[(3-Trifluromethylphenyl)(chloro)phenylmethyl]-1,4,5,6,-tetrahydropyrimidine A solution of Phenyl-(1,4,5,6-tetrahydro-pyrimidin-2-yl)-3-trifluromethyl-phenyl)-methanol (4.5 g, 13 mmol) in CHCI3 was treated with SOCI2 (3 ml) heated at reflux temperature for 4 h, cooled to room temperature and concenterated in vacuo to give 2-[(3-trifluromethylphenyl)(chloro)phenylmethyl]-1,4,5,6,-tetrahydropyrimidine as a yellow solid (4.5 g, 96% yield). MS m/e 255 (M)+; 1HNMR (DMSO-d6,300 MHz) 8 1.95 (m, 2H), 3.5 (m, 5H), 7.39 (m, 2H), 7.5 (m, 3H), 7.7 (m, 2H), 7.85 (m, 1H), 9.6 (b, 2H). Step d) 2-[(3-Trifluromethylphenyl)(phenyl)]-1,4,5,6,-tetrahydropyrimidin-2-ylmethylamine Into a container, cooled to - 30 °C, was added 2-[(3- trifluromethylphenyl)-(chloro)phenylmethyl]-1,4,5,6,-tetrahydropyrimidine (2g, 5.6 mmol) and ammonia dissolved in isopropyl alcohol 8N (20 ml). The container was sealed, heated to 60°C for 16 h and cooled to room temperature. The reaction mixture was removed and concentrated in vacua. The residue was dispersed in 2.5N NaOH ano extracted with CH2CI2. The extracts were combined, dried over MgSO4and concentrated in vacuo to give 2-[(3-trifluromethylphenyl)(phenyl)]-1,4,5,6,-tetrahydropyrimidin-2-ylmethylamine as a brown oil (1.5g. MS m/e 334 (M)+. Step e) 8-Phenyl-8-[3-(trifluoromethyl)phenyl]-2,3,4,8-tetrahydroimidazo [1,5-a]pyrimidin-6-amine A solution of 2-[(3-trifluromethylphenyl)(phenyl)]-1,4,5,6,-tetrahydropyrimidin-2-ylmethylamine (1.3 g, 3.9 mmol) in CHCI3 was treated with BrCN (1.6 g, 15.6 mmol), heated at reflux temperature for 48 h, cooled to room temperature and poured into NaOH 2.5N. The phases were separated and the aqueous phase was extracted with CHCI3. The extracts were combined with the original organic phase, dried over MgSO4 and concenterated to dryness. The resultant residue was purified by flash chromatography on silica gel in; isopropyl alcohol/ ethanol/ methylene chloride/ triethyl amine (6:2:2:1 drop) to give the title product as a light brown solid (0.2 g, 20% yield) was recovered. MS m/e 357 (MX; 1HNMR (DMSO-d6,300 MHz) δ 1.75 (m, 2H), 3.4 (m, 2H), 3.6 (m, 2H), 7.2 (m, 3H), 7.5 (m, 4H), 7.95 (m, 2H). EXAMPLE 7 Preparation of 8-(3-Methoxyphenvl)-8-phenvl-2.3.4.8-tetrahvdroimidazof1.5- alpyrimidin-6-amine Step a) Phenyl-(1,4,5,6-tetrahydro-pyrimidin-2-yl)-3-methoxy-phenyl)-methanol Using essentially the same procedure described in Example 6, step b, and employing 2-(4,5,6-tetrahydropyrimidyl) phenyl ketone and 3-methoxy- phenyl magnesium bromide, phenyl-(1,4,5,6-tetrahydro-pyrimidin-2-yl)-3-methoxy-phenyl)-methanol was obtained as a light brown solid. 1HNMR (DMSO-d6, 300 MHz) δ 1.8 (m, 2H), 3.4 (m, 4H), 3.75 (s, 3H), 6.95 (m, 3H), 7.3 (m, 3H), 7.4 (m, 3H). Step b) 2-[(3-Methoxy-phenyl)(chloro)phenylmethyl]-1,4,5,6,-tetrahydropyrimidin Using essentially the same procedure described in Example 6, step c, and employing phenyl-(1 ,4,5,6-tetrahydro-pyrimidin-2yl)-3-methoxy-phenyl)-methanol, 2-[(3-methoxy-phenyl)(chloro)phenylmethyl]-1,4,5,6,-tetrahydropyrimidin was obtained as a brown solid. 1HNMR (DMSO-d6,300 MHz) δ 1.95 (m, 2H), 3.4 (m, 4H), 3.75 (s, 3H), 6.8 (s, 1H), 6.9 (dd, 1H), 7.1 (dd, 1H), 7.4 (m, 4H), 7.5 (m, 4H), 9.4 (b, 2H). Step c) 2-[(3-Methoxyphenyl)(phenyl)]-1,4,b,6,-tetrahydropyrimidin-2-ylmethylamine Using essentially the same procedure described in Example 6, step d, and employing 2-[(3-methoxyphenyl)(chloro)phenylmethyl]-1,4,5,6,-tetrahydropyrimidine, 2-[(3-methoxyphenyl)(phenyl)]-1 ,4,5,6.-tetrahydropyrimidin^-ylmethylamine was obtained as a brown oil. MS m/e 296 (M)+. Step d) 8-(3-methoxyphenyl)-8-phenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine Using essentially the same procedure described in Example 6, step e, and employing 2-[(3-methoxyphenyl)(phenyl)]-1,4,5,6,-tetrahydropyrimidin-2-ylmethylamine, the title compound was obtained as a white solid. MS m/e 319 (M)"; 1HNMR (DMSO-d6, 300 MHz) δ 1.6 (m, 2H), 3.3 (m, 2H), 3.5 (m, 2H), 3.6 (s, 3H), 6.7 (m, 1H), 7.05 (m, 2H), 7.1 (m, 2H), 7.1 (m, 2H), 7.4 (d, 2H). EXAMPLE 8 Preparation of 7-(4-IVIethoxv-3-methvlphenvl)-7-f3-propoxvphenvn-2.7-dihvdro-3H- imidazof 1.5-a]imidazol-5-amine Step a) Ethyl 2-hydroxy-2-(4-methoxy-3-methylphenyl)ethanimidoate hydrochloride A mixture of 4-methoxy-3-methylbenzaldehyde (17.6 ml) and trimethylsilyl cyanide (18.7 ml) was treated with zinc iodide (0.600 g), stirred for 3 h, treated with diethyl ether and filtered through a cellite pad. The filtrate was evaporated. The resultant residue was dissolved in absolute ethanol, cooled to -20 °C and saturated with gaseous hydrogen chloride (40 g). The solution was slowly warmed up to room temperature and concentrated in vacuo. The resultant residue was triturated with diethyl ether and filtered. The filtercake was dried under vacuum to give ethyl 2-hydroxy-2-(4-methoxy-3-methylphenyl)ethanimidoate hydrochloride as a yellow solid (28.55 g), characterized by LCMS analysis. LCMS Conditions: HP 1100 HPLC system; Waters Xterra MS C18, 2 mm (i.d.) x 50 mm (length), 3.5 um column, set at 50°C; Flow rate 1.0 mL/min; Solvent A: 0.02% NH4OH in water; Solvent B 0.02% NH4OH in ACN; Gradient: Time O: 10% B; 2.5 min 90% B; 3 min 90% B; Sample concentration: ~2.0mM; Injection volume: 5uL; Detection: 220nm, 254nm DAD. Step b) [4,5-Dihydro-1 W-imidazol-2-yl(4-methoxy-3-methylphenyl)(3-propoxyphenyl)methyl]amine Using a procedure analogous to the one disclosed in U.S. 3926994 and employing ethyl 2-hydroxy-2-(4-methoxy-3-methylphenyl)ethanimidoate hydrochloride salt with 1,2-ethyldiamine, and subsequent reaction with 3-propyloxy phenylmagnesium bromide was dissolved in chloroform (20 ml) gave a reaction mixture. Diisopropylethylamine (2 ml) wa:. added to the reaction mixture, followed by thionyl chloride (1 ml). After 1 hour the reaction mixture was diluted with acetonitrile and cooled to -78°C. The reaction solution was saturated with gaseous ammonia (20 g). The flask was sealed and warmed up to room temperature. After 1 hour the solution was again_cooled down to -78°C and the ammonia was slowly evaporated. Following the removal of ammonia, the remaining solvents were evaporated and the residue was taken up in ethyl acetate, filtered through a pad of silica. The silica pad was eluted with ethyl acetate, then with (40/5/5) ethyl acetate/methanol/ammonium hydroxide. The eluents were combined and concentrated in vacua to afford [4,5-Dihydro-1H-imidazol-2-yl(4-methoxy-3-methylphenyl)(3-propoxyphenyl)methyl]amine as a yellow amorphous solid (0.6 g), characterized by LCMS analysis. LCMS Conditions: HP 1100 HPLC system; Waters Xterra MS C18, 2 mm (i.d.) x 50 mm (length), 3.5 um column, set at 50°C; Flow rate 1.0 mL/min; Solvent A: 0.02% NH4OH in water; Solvent B 0.02% NH4OH in ACN; Gradient: Time O: 10% B; 2.5 min 90% B; 3 min 90% B; Sample concentration: ~2.0mM; Injection volume: 5uL; Detection: 220nm, 254nm DAD. Step c) 7-(4-Methoxy-3-methylphenyl)-7-(3-propoxyphenyl)-2,7-dihydro-3H-imidazo[1,5-a]imidazol-5-amine. A solution of [4,5-dihydro-1H-imidazol-2-yl(4-methoxy-3-methylphenyl)(3-propoxyphenyl)methyl]amine (0.6 g) in chloroform is treated with cyanogen bromide (0.581 g), heated at 60°C for 5 days and filtered through a pad of silica. The silica pad was eluted with ethyl acetate, followed by elution with (40:5:5) ethyl acetate: methanol: ammonium hydroxide. The eluents were combined and concentrated in vacuo to give a thick yellow oil, which was purified by Gilson preparative reverse phase HPLC system YMC Pro C18, 20 mm x 50 mm ID, 5 uM column; 2 ml injection; Solvent A: 0.02% NH4OH/water; Solvent B:0.02% NH4OH/acetonitrile; Gradient: Time 0: 95% A; 2 min: 95% A; 14 min: 10% A, 15 min: 10% A, 16 min: 95% A; Flow rate 22.5 mL/min; Detection: 254 nm DAD to afford the title compound was as an off-white, amphorous solid (0.131 g), characterized by LCMS analysis. LCMS Conditions: HP 1100 HPLC system; Waters Xterra MS C18, 2 mm (i.d.) x 50 mm (length), 3.5 um column, set at 50°C; Flow rate 1.0 mL/min; Solvent A: 0.02% NH4OH in water; Solvent B 0.02% NH4OH in ACN; Gradient: Time O: 10% B; 2.5 min 90% B; 3 min 90% B; Sample concentration: ~2.0mM; Injection volume: 5uL; Detection: 220nm, 254nm DAD; retention time: 2.34 min, [M-H] 377, [M+H] 379. EXAMPLE 9 Preparation of 8-(4-Methoxv-3-methvlphenvn-8-(3-propoxyphenvl)-2.3.4.8- tetrahvdroimidazo f1.5-alpyrimidin-6-amine Using essent ally the same procedure described in Example 8 and employing 1,3-propyldiamine in place of 1,2-ethyldiamine, the title compound was obtained as an off-white, amorphous solid, characterized by LCMS analysis. LCMS Conditions: HP 1100 HPLC system; Waters Xterra MS C18, 2 mm (i.d.) x 50 mm (length), 3.5 um column, set at 50°C; Flow rate 1.0 mL/min; Solvent A: 0.02% NH4OH in water; Solvent B 0.02% NH4OH in ACN; Gradient: Time O: 10% B; 2.5 min 90% B; 3 min 90% B; Sample concentration: ~2.0mM; Injection volume: 5uL; Detection: 220nm, 254nm DAD; (retention time: 2.43 min, [M-H] 391, [M+H] 393. EXAMPLE 10 Preparation of 8-(4-Methoxv-3-methvlphenvl)-3.3-dimethvl-8-(3-propoxyphenyl)- 2.3.4.8-tetrahvdroimidazof1.5-a1pvrimidin-6-amine Using essentially the same procedure described in Example 8 and employing 1,3-diamino-2,2-dimethylpropane in place of 1,2-ethyldiamine, the title compound was obtained as an off-white, amorphous solid, characterized by LCMS analysis. LCMS Conditions: HP 1100 HPLC system; Waters Xterra MS C18, 2 mm (i.d.) x 50 mm (length), 3.5 um column, set at 50°C; Flow rate 1.0 mL/min; Solvent A: 0.02% NH4OH in water; Solvent B 0.02% NH4OH in ACN; Gradient: Time O: 10% B; 2.5 min 90% B; 3 min 90% B; Sample concentration: ~2.0mM; Injection volume: 5uL; Detection: 220nm, 254nm DAD; (retention time: 2.74 min, [M-H] 419, [M+H] 421). EXAMPLE 11 Preparation of 8.8-Diphenvl-2.3.4.8-tetrahvdroimidazo[ 1,5a]pyrimidin-6-amine Using essentially the same procedure described in Example 8 and employing benzaldehyde, 1,3-propyldiamine and phenylmagnesium bromide, the title compound is obtained, 1H NMR (400 MHZ, DMSOd6) δ1.62 (m, 2H), 3.4 (t, 2H), 3.58 (t, 2H), 6.2 (brs, 2H), 7.15 (m, 2H), 7.3 (m, 4H), 7.55 (m, 4H); MS m/e (M)+291. EXAMPLE 12 Preparation of 8-r3-(2-Cvclopropvl-ethvl)-phenvn-8-f4-trifluoromethoxv-phenyl)- 2.3.4.8-tetrahvdro-imidazoM.5-al]pvrimidin-6-vlamine (Formula Removed) Preparation of Compound 2 A mixture of 3-cyclopropyl-1-propyne (1.00 g, 15.1 mmol) and catechol borane (2.72 g, 22.6 mmol) in tetrahydrofuran (70 ml) was heated at reflux for 3 h, cooled to room temperature and concentrated. Purification by flash chromatography (silica 1:1 hexanes/ethyl acetate afforded 1.05 g of 2 as a colorless syrup which was ~50% pure as determined by 1H NMR: 1H NMR (300 MHz, CDCI3) δ 7.22-7.16 (m, 2H), 7.08-7.02 (m, 2H), 6.45 (dd, J = 17.8, 9.4 Hz, 1H), 5.84 (d, J = 17.8 Hz, 1H), 1.72-1.62 (m, 1H), 0.98-0.89 (m, 2H), 0.68-0.61 (m, 2H). Preparation of Compound 4 A mixture of 3 (0.106 g, 0.23 mmol), 2 (0.130g, -50 % purity, 0.35 mmol), bis(triphenylphosphino)palladium(ll) chloride (0.008 g, 0.011 mmol), triphenylphosphine (0.006 g, 0.023 mmol) and sodium carbonate (0.073 g, 0.69 mmol) in 3:1 DME/water (8 mL) was heated at 80 °C for 2 h. The reaction was cooled to room temperature, concentrated and the residue diluted with ethyl acetate (50 ml) and water (20 ml). The organic layer was separated and washed with brine (20 ml), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 95:5:0.5 methylene chloride/methanol/concentrated ammonium hydroxide) afforded 4 (0.073 g 72%) as a white solid: 1H NMR (300 MHz, CDCI3) 8 7.47 (d, J = 8.8 Hz, 2H), 7.36 (br s, 1H), 7.27-7.18 (m , 3H), 7.12 (d, J = 8.6 Hz, 2H), 6.42 (d, J = 15.7 Hz, 1H), 5.69 (dd, J 15.7, 8.9 Hz, 1H), 3.68-3.53 (m, 4H), 2.00-1.85 (m, 2H), 1.58-1.48 (m, 1H), 0.82-0.77 (m, 2H), 0.50-0.44 (m, 2H); ESI MS m/z441 [C24H23F3N4O+H]+ Preparation of 8-[3-(2-Cyclopropyl-ethyl)-phenyl]-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5-a]pyrimidin-6-ylamine A mixture of 4 (0.073 g, 0.16 mmol) and palladium on carbon (0.020 g, 10 wt%, wet) in ethyl acetate was shaken under an atmosphere of hydrogen (15 psi) for 2.75 h. The reaction mixture was filtered through celite and the filtrate concentrated. Purification by flash chromatography (silica, 95:5:0.5 methylene chloride/methanol/concentrated ammonium hydroxide) followed by freeze-drying from acetonitrile/water (1:1, 4 ml) afforded 0.038 g of a white solid. This solid was further purified by semi-preparative chromatography (method 3), the appropriate fractions were combined and neutralized with 10 % aqueous sodium carbonate. The acetonitrile was removed under reduced pressure and the residue extracted with methylene chloride (3 x 20 ml). The combined organic layers were washed with brine (25 ml), dried over sodium carbonate, filtered and concentrated and then freeze-dried from acetonitrile/water (1:1, 4 ml) to afford the title product as a white solid, 0.024 g (33% yield), mp 65-77 °C; 1H NMR (500 MHz, CD3OD) 8 7.42 (d, J = 8.8 Hz, 2H), 7.23-7.10 (m, 6H), 3.69 (t, J = 6.0 Hz, 2H), 3.47 (t, J = 5.5 Hz, 2H), 2.66 (t, J = 7.5 Hz, 2H), 1.90-1.82 (m, 2H), 1.45 (dd, J = 15.0, 7.0 Hz, 2H), 0.68-0.61 (m, 1H), 0.38-0.34 (m, 2H), -0.01--0.03 (m, 2H); ESI MS m/z443 [C24H25F3N4O+H]+ EXAMPLE 13 Preparation of 8-(3-Allylphenvn-8-f4-trifluoromethoxvphenvn-2.3.4.8-tetrahvdro- imidazon[1.5-a]pyrimidin-6-vlamine (Formula Removed) A mixture of 1 (0.700 g, 1.54 mmol), allyltributyltin (0.611 g, 1.85 mmol), palladium chloride (0.013 g, 0.08 mmol) and triphenylphosphine (0.081 g, 0.31 mmol), in DMF (6.0 ml) was degassed then heated at 110 °C for 17 h. The mixture was cooled to room temperature, diluted with diethyl ether (100 ml) and washed with water (2 * 30 ml) and brine (50 ml), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 97:2.5:0.5 methylene chloride/methanol/concentrated ammonium hydroxide) afforded 2 (0.353 g, 55%) as a white solid. A portion (0.065 g) of this material was further purified by semi-preparative LC (Method 3). The appropriate fractions were combined and neutralized with saturated aqueous sodium carbonate (10 mL), most of the acetonirile was removed and the mixture then extracted with methylene chloride (3 * 25 ml_). The combined organic layers were dried over sodium sulfate, filtered and concentrated and then freeze-dried from 2:1 acetonitrile/water (3 mL) t: afford the title product as a white solid, 0.027 g, mp 89-111 °C; 1H NMR (500 MHz, CD3OD) δ 7.42 (d, J = 6.9 Hz, 2H), 7.25-7.10 (m, 6H), 5.96-5.88 (m, 1H), 5.07-4.99 (m, 2H), 3.68 (t, J = 5.9 Hz, 2H), 3.47 (t, J = 4.6 Hz, 2H), 3.34-3.29 (m, 2H), 1.88-1.84 (m, 2H); ESI MS m/z415 [C22H21F3N4O + H]+. EXAMPLE 14 Preparation of 8-(3-Propvl-phenvl)-8-(4-trifluoromethoxv-phenvl)-2.3.4.8- tetrahvdro-imidazof1.5-a]pyrimidin-6-vlamine (Formula Removed) Preparation of Compound 2 A mixture of 1 (0.288 g, 0.70 mmol), 4-dimethylaminopyridine (0.085 g, 0.70 mmol) and di-tert-butyld (carbonate (0.379 g, 1.74 mmol) in tetrahydrofuran (10 ml) was stirred at room temperature for 17 h. The mixture was diluted with methylene chloride (75 ml) and washed with 1 N citric acid solution (2 x 25 ml) and brine (50 mL), dried over sodium sulfate, filtered and concentrated to afford 2 (0.38 g, 89%) as a yellow oil: 1H NMR (500 MHz, CDCI3) 5 7.57 (d, J = 8.7 Hz, 2H), 7.43-7.15 (m, 6H), 5.96-5.88 (m, 1H), 5.07-5.02 (m, 2H), 3.76-3.67 (m, 4H), 3.37 (d, J = 6.7 Hz, 2H), 1.89-1.83 (m, 2H), 1.37 (s, 18H); ESI MS m/z615[C32H37F3N4O5+H]+ Preparation of Compound 3 A mixture of 2 (0.088 g, 0.14 mmol) and palladium on carbon (0.020 g, 10 wt%, wet) in ethanol was shaken under an atmosphere of hydrogen (20 psi) for 1 h. The reaction mixture was then filtered through celite and the filtrate concentrated to afford 3 (0.075 g, 86%) as a colorless oil: 1H NMR (500 MHz, CDCI3) δ 7.53-7.46 (m, 2H), 7.31- 7.05 (m, 6H), 3.68-3.59 (m, 2H), 3.57-3.46 (m, 2H), 2.60-2.51 (m, 2H), 1.87-1.82 (m, 2H), 1.65-1.53 (m, 2H), 1.35 (s, 18H), 0.97-0.84 (m, 3H); FSI MS m/z 617 [C32H39F3N4O5+H]+ Preparation of 8-(3-Propyl-phenyl)-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5-a]pyrimidin-6-ylamine A solution of 3 (0.075 g, 0.12 mmol) in 4 M HCI/dioxane (2 ml) was stirred at room temperature for 17 h. The reaction was concentrated and partitioned between methylene chloride (25 ml) and saturated aqueous sodium bicarbonate (25 ml). The organic layer was separated and washed with brine (20 mL), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 97:2.5:0.5 methylene chloride/methanol/concentrated ammonium hydroxide) afforded a colorless oil, 0.055 g (100% yield). The oil was freeze-dried from 2:1 acetonitrile/water (3 ml) to afford the title product as a white solid, 0.035 g, mp 75-79 °C; 1H NMR (500 MHz, CD3OD) 8 7.42 (dt, J = 8.9, 2.9 Hz, 2H), 7.23-7.19 (m, 3H), 7.14-7.09 (m, 3H), 3.68 (t, J = 5.9 Hz, 2H), 3.48-3.46 (m, 2H), 2.54 (t, J = 7.4 Hz, 2H), 1.88-1.84 (m, 2H), 1.61-1.56 (m, 2H), 0.90 (t, J= 7.3 Hz, 3H); ESI MS m/z 417 [C22H23F3N4O+H]+ EXAMPLE 15 Preparation of 3-r6-Amino-8-(4-trifluoromethoxv-phenvl)-2.3.4.8-tetrahvdro- imidazon.5-alpvrimidin-8-vn-N-ethvl-benzamide (Formula Removed) Preparation of Compound 2 A mixture of 1 (0.95 g, 1.94 mmol) and 3 N HCI (25 ml) was heated at reflux for 30 min. After this time, the reaction mixture was cooled to room temperature and concentrated to dryness. To the residue obtained was added 20% aqueous KOH (10 mL) and methanol (10 mL) and the mixture heated at reflux for 30 min. The mixture was then cooled to room temperature, concentrated to remove most of the methanol, acidified with concentrated HCI, and the solid that formed was collected by filtration and dried to afford 2 (0.83 g, 97%) as a white solid: 1H NMR (5(0 MHz, CD3OD) 6 8.11-8.03 (m, 2H), 7.61-7.54 (m, 2H), 7.47-7.44 (m, 2H), 7.39-7.33 (m, 2H), 4.00 (m, 2H), 3.62 (M, 2H), 2.06 (m, 2H); ESI MS m/z436 [C20H16F3N3O3S+H]+ Preparation of Compound 3 Oxalyl chloride (0.12 g, 0.96 mmol) was added to a suspension of 2 (0.20 g, 0.46 mmol) in methylene chloride (3.0 ml). Dimethylformamide (1 drop) was added and the mixture stirred at room temperature for 2 h and then the solvents were removed. The residue was suspended in methylene chloride (3 ml) and diisopropyl ethylamine (0.148 g, 1.15 mmol) was added, followed by ethylamine (0.25 ml of a 2.0 M solution in THF, 0.50 mmol) and the reaction stirred for 2 h. The mixture was diluted with water (30 ml) and methylene chloride (30 mL). The organic layer was separated and washed with 1 N HCI (15 mL), saturated aqueous sodium bicarbonate (15 mL) and brine (15 mL), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, ethyl acetate) afforded 3 (0.085 g, 40%) as a white solid: 1 H NMR (500 MHz, CD3OD) 8 7.81-7.77 (m, 2H), 7.53-7.42 (m, 4H), 7.33-7.27 (m, 2H), 3.95-3.84 (m, 2H), 3.58-3.51 (m, 2H), 3.38 (q, J= 7.2 Hz, 2H), 1.97-1.89 (m, 2H), 1.19 (t, J= 7.2 Hz, 3H); Preparation of 3-[6-Amino-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5-a]pyrimidin-8-yl]-N-ethyl-benzamide A mixture of 3 (0.085 g, 0.18 mmol) and f-butyl hydroperoxide (0.49 g of a 70% solution in water, 5.50 mmol) in methanol (10 mL) and concentrated aqueous ammonium hydroxide (2 mL) was stirred overnight at room temperature. After this time, 10% aqueous sodium thiosulfate (2 mL) was added; the mixture concentrated to remove most of the methanol and then the aqueous mixture was extracted with methylene chloride (2 30 mL). The methylene chloride extracts were combined and washed with brine (30 mL), dried over magnesium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 95:5:0.25 methylene chloride/methanol/concentrated ammonium hydroxide) afforded a white solid which was freeze-dried from 1:1 acetonitrile/water (4 mL) to afford the title product as a white solid, 0.041 g (52% yield), mp 129-136 °C; 1 H NMR (500 MHz, CDCI3) δ 7.88 (t, J= 1.7 Hz, 1H), 7.71 (dt, J = 6.3, 1.5 Hz, 1H), 7.64 (dt, J = 6.6, 1.6 Hz, 1H), 7.48 (d, J = 8.9 Hz, 2H), 7.38 (t, J = 7.7 Hz, 1 H), 7.14 (d, J = 8.1 Hz, 2H), 6.36 (br s, 1 H), 3.62 (t, J = 6.0 Hz, 2H), 3.59 (t, J = 5.6 Hz, 2H), 3.49-3.42 (m, 2H), 1.89 (quintet, J = 5.8 Hz, 2H), 1.22 (t, J = 7.2 Hz, 3H); ESI MS m/z 446 EXAMPLE 16 Preparation of N-{3-r6-Amino-8-i4-trifluoromethoxv-phenvl)-2.3.4.8-tetrahvdro- imidazon.5-a1pvrimidin-8-vn-phenvl}-propionamide hvdrochloride (Formula Removed) Preparation of Compound 2 A mixture of 1 (3.00 g, 25.4 mmol), allyl bromide (9.22 g, 76.2 mmol), and potassium carbonate (10.5 g, 76.2 mmol) in dimethylformamide (30 ml) was heated at reflux for 18 h. The reaction was then cooled to room temperature, diluted with water (100 mL) and extracted with ethyl acetate (2 x 150 ml). The organic extracts were combined and washed with brine (3 x 100 ml), dried over sodium sulfate, filtered and concentrated under reduced pressure. Purification by flash chromatography (silica, 95:5 hexanes/ethyl acetate) afforded 2 (4.10 g, 81%) as a yellow oil: 1H NMR (500 MHz, CDCI3) δ 7.23 (m, 1H), 6.92 (d, J = 7.4 Hz, 1H), 6.88-6.81 (m, 2H), 5.88-5.76 (m, 2H), 5.23-5.10 (m, 4H), 3.93 (t, J = 2.3 Hz, 4H); ESI MS m/z 199 [C13H14N2 + H]+. Preparation of Compound 4 A mixture Df magnesium (0.271 g, 11.3 mmol) and a small crystal of iodine in THF (7 mL) was neated to 50 °C and treated dropwise with a solution of 3 (2.74 g, 11.3 mmol) in THF (15 ml) over a period of 10 min. After stirring at 50 °C for an additional 2 h, the mixture was cooled to room temperature and treated with a solution of 2 (1.50 g, 7.57 mmol) in THF (15 ml). The mixture was then reheated to 65 °C for 2 h. After this time, the reaction was cooled to room temperature then placed in an ice bath and anhydrous methanol (30 ml) was added. After stirring for 30 min at ice bath temperature, sodium borohydride (0.573 g, 15.1 mmol) was added portionwise, the cooling bath was removed and the mixture stirred at room temperature for 2 h. Saturated aqueous ammonium chloride (15 ml) was then added and most of the methanol and THF were removed under reduced pressure. The resulting aqueous mixture was extracted with methylene chloride (2 x 100 ml), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 1:1 ethyl acetate/hexane) afforded 4 (1.16 g, 42%) as an orange syrup: 1H NMR (500 MHz, CDCI3) δ 7.41 (d, J = 4.9 Hz, 2H), 7.16-7.10 (m, 3H), 6.67 (s, 1H), 6.64 (d, J = 7.5 Hz, 1H), δ.57 (dd, J= 5.7, 2.6 Hz, 1H), 5.87-5.75 (m, 2H), 5.15 (t, J= 1.7 Hz, 1H), 5.13 (t, J = 1.6 Hz, 1 H), 5.11 (d, J = 2.5 Hz, 3H), 3.89 (d, J= 4.8 Hz, 4H), 1.73 (br s, 2H); ESI MS m/z 363 [C20H21F3N2O + H]+. Preparation of Compound 5 A mixture of 4 (1.16 g, 3.20 mmol) in methylene chloride (15 ml) and saturated aqueous sodium bicarbonate (15 ml) was cooled with an ice bath, treated with thiophosgene (0.405 g, 3.52 mmol) and stirred vigorously for 1 h. The organic layer was separated, washed with brine (20 mL), dried over sodium sulfate, filtered and concentrated to afford 5 (1.26 g, 98%) as a brown syrup: 1H NMR (500 MHz, CDCI3) 8 7.34 (d, J = 4.9 Hz, 2H), 7.22-7.14 (m, 3H), 6.63 (d, J = 5.8 Hz, 1H), 6.59-6.54 (m, 2H), 5.88 (s, 1H), 5.86-5.77 (m, 2H), 5.18-5.11 (m, 4H), 3.93-3.88 (m, 4H); ESI MS m/z 405 [C2iH19F3N2OS + H]+. Preparation of Compound 6 To a mixture of potassium f-butoxide (0.38 g, 3.38 mmol) in THF (15 ml) at -78 °C was added dropwise a solution of 5 (1.24 g, 3.07 mmol) and carbon disulfide (0.35 g, 4.61 mmol) in THF (15 ml), over a period of 10 min. The reaction was stirred at -78 °C for 30 min, then warmed to room temperature slowly and stirred for 20 h. The reaction was then concentrated to remove most of the THF and the residue diluted with ethyl acetate (75 mL), water (75 mL) and 1 N HCI (30 mL). The organic layer was separated, washed with brine (30 mL), dried over sodium sulfate, filtered and concentrated to afford 6 (1.58 g, 100%) as a red syrup: 1H NMR (300 MHz, CDCI3) δ 7.36 (m, 2H), 7.24-7.06 (m, 3H), 6.74-6.53 (m, 3H), 5.88-5.68 (m, 2H), 5.17-5.06 (m, 4H), 3.95-3.81 (m, 4H); ESI MS m/z483 [C22H19F3N2OS3 + H]+. Preparation of Compound 7 A mixture of 6 (1.48 g, 3.08 mmol) and 1,3-diaminopropane (0.68 g, 9.24 mmol) in ethanol (36 mL) was heated at 70 °C for 1 .5 h. The reaction was then cooled to room temperature, concentrated and the residue partitioned between ethyl acetate (150 mL) and water (75 mL). The organic layer was separated and washed with brine (75 mL), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 1:3 ethyl acetate/hexanes) afforded 7 (0.622 g, 41%) as a yellow solid: 1H NMR (500 MHz, CDCI3) 8 7.41 (d, J = 5.0 Hz, 2H), 7.20-7.13 (m, 3H), 7.04 (br s, 1 H), 6.64 (dd, J = 6.0, 2.4 Hz, 1 H), 6.61 (t, J = 1 .9 Hz, 1 H), 6.53 (d, J = 6.6 Hz, 1H), 5.83-5.72 (m, 2H), 5.14-5.05 (m, 4H), 3.92-3.81 (m, 6H), 3.63-3.51 (m, 2H), 1.89 (q, J= 5.8 Hz, 2H); ESI MS m/z489 [C25H25F3N4OS +H]+. Preparation of Compound 8 A mixture of 7 (0.408 g, 0.84 mmol), N,N--dimethylbarbaturic acid (0.786 g, 5.03 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.019 g, 0.017 mmol) in dichloromethane (2.0 mL) was heated at 35 °C for 3 h. The reaction was then cooled to room temperature, concentrated and the residue partitioned between ether (80 mL) and 10% aqueous sodium carbonate (30mL). The organic layer separated and washed with 10% aqueous sodium carbonate (30 mL), dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 95:5:0.25 methylene chloride/methanol/concentrated ammonium hydroxide) afforded 8 (0.278 g, 82%) as a yellow solid: 1H NMR (500 MHz, CDCI3) δ7.39 (d, J = 6.8 Hz, 2H), 7.19-7.09 (m, 4H), 6.67-6.61 (m, 3H), 3.88 (t, J = 6.0 Hz, 2H), 3.72 (s, 2H), 3.58 (q, J = 6.1 Hz, 2H), 1.89 (q, J = 5.5 Hz, 2H); ESI MS m/z407 [C19H17F3N4OS +H]+. Preparation of Compound 9 A mixture of 8 (0.100 g, 0.246 mmol) in dichloromethane (2.0 mL) was cooled to 0 °C and propionyl chloride (0.025 g, 0.270 mmol) and diisopropylethylamine (0.048 g, 0.369 mmol) were added. After stirring at 0 °C for 1 h the reaction was partitioned between dichloromethane (30 mL) and water (20 mL). The organic layer was separated and then washed with 1 N hydrochloric acid (20 ml), saturated aqueous sodium bicarbonate (20 ml), and brine (20 ml) dried over sodium sulfate, filtered and concentrated. Purification by flash chromaiography (silica, 1:1 ethyl acetate/hexanes) afforded 9 (0.044 g, 39%) as a yellow oil: 1H NMR (500 MHz, CDCI3) 8 7.70 (d, J = 7.5 Hz, 1H), 7.41-7.31 (m, 4H), 7.17 (d, J= 7.0 Hz, 4H), 7.04 (d, J = 7.4 Hz, 1H), 3.89 (t, J = 6.0 Hz, 2H), 3.65-3.54 (m, 2H), 2.36 (q, J = 7.5 Hz, 2H), 1.23 (q, J = 7.5 Hz, 3H); ESI MS m/z463 C22H21F3N4O2S+H]+ Preparation of A/-{3-[6-Amino-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5-a]pyrimidin-8-yl]-phenyl}-propionamide hydrochloride A mixture of 8 (0.040 g, 0.086 mmol) and t-butyl hydroperoxide (0.33 g of a 70% solution in water, 2.59 mmol) in methanol (4.0 ml) and concentrated aqueous ammonium hydroxide (1.0 ml_) was stirred overnight at room temperature. After this time, 10% aqueous sodium thiosulfate (5 ml) was added; the mixture concentrated to remove most of the methanol and then the aqueous mixture was extracted with methylene chloride (3 *20 ml). The methylene chloride extracts were dried over sodium sulfate, filtered and concentrated. Purification by flash chromatography (silica, 95:5:0.25 methylene chloride/methanol/concentrated ammonium hydroxide) afforded 0.017 g of a white solid. This material was then dissolved in 1 N hydrochloric acid (3 mL) and freeze-dried to afford the title product as a white solid, 0.022 g (54% yield), mp 148-150 °C; 1H NMR (500 MHz, CD3OD) D7.85 (d, J= 1.9 Hz, 1H), 7.50-7.59 (m, 3H), 7.47-7.37 (m, 3H), 7.07 (d, J = 5.0 Hz, 1H), 3.91-3.04 (m, 2H), 3.81-3.66 (m, 2H), 2.44-2.34 (m, 2H), 2.19-2.10 (m, 2H), 1.21-1.16 (m, 3H); ESI MS m/z 446 [C22H22F3N5O2+H]+ EXAMPLE 17 Evaluation of BACE-1 Binding Affinity of Test Compounds 1 . Fluorescent Kinetic Assays Final Assay Conditions: 10 nM human BACE1 (or 10 nM Murine BACE1, 1.5 nM human BACE2), 25 uM substrate (WABC-6, MW 1549.6, from AnaSpec), Buffer: 50 mM Na-Acetate, pH 4.5, 0.05% CHAPS, 25% PBS, room temperature. Na-Acetate was from Aldrich, Cat.# 24,124-5, CHAPS was from Research Organics, Cat. # 1304C 1X, PBS was from Mediatech (Cellgro), Cat# 21-031-CV, peptide substrate AbzSEVNLDAEFRDpa was from AnaSpec, Peptide Name: WABC-6 Determination of stock substrate (AbzSEVNLDAEFRDpa) concentration: ~ 25 mM stock solution is made in DMSO using the peptide weight and MW, and diluted to ~25 μM (1:1000) in 1X PBS. Concentration is determined by absorbance at 354 nm using an extinction coefficient D of 18172 M~1cm~1, the concentration of stock substrate is corrected, and the substrate stock : tored in small aliquots in -80° C. [Substrate Stock] = ABS 354nm * 10 /18172 (in mM) The extinction coefficient ε354 nm was adapted from TACE peptide substrate, which had the same quencher-fluorophore pair. Determination of Stock Enzyme Concentration: the stock concentration of each enzyme is determined by absorbance at 280 nm using an e of 64150 M~1cm~1 for hBACEl and MuBACEl, 62870 M'W for hBACE2 in 6 M Guanidinium Hydrochloride (from Research Organics, Cat. # 5134G-2), pH ~ 6. The extinction coefficient e280nm for each enzyme was calculated based on known amino acid composition and published extinction coefficients for Trp (5.69 M"1 cm"1) and Tyr (1.28 M"1 cm"1) residues (Anal. Biochem. 182, 319-326). Dilution and mixing steps: total reaction volume: 100 uL 2X inhibitor dilutions in buffer A (66.7 mM Na-Acetate, pH 4.5, 0.0667% CHAPS) were prepared, 4X enzyme dilution in buffer A (66.7 mM Na-Acetate, pH 4.5, 0.0667% CHAPS) were prepared, 100 uM substrate dilution in 1X PBS was prepared, and 50 uL 2X Inhibitor, 25 uL 100 uM substrate are added to each well of 96-well plate (from DYNEX Technologies, VWR #: 11311-046), immediately followed by 25 uL 4X enzyme (added to the inhibitor and substrate mix), and the fluorescence readings are initiated. Fluorescence Readings: Readings at λ,ex 320 nm and λ,em 420 nm are taken every 40 sec for 30 min at room temperature and the linear slope for substrate cleavage rate (Vj) determined. Calculation of % Inhibition: % Inhibition = 100 *(1-vi/v0) v^ substrate cleavage rate in the presence of inhibitor v0: substrate cleavage rate in the absence of inhibitor ICgn Determination: % Inhibition = ((B * IC50n) + (100 * I0n)) / (IC50n + I0n) (Model # 39 from LSW Tool Bar in Excel, where B is the % inhibition from the enzyme control, which should be close to 0.) % Inhibition is plotted vs. Inhibitor Concentration (I0) and the data fit to the above equation to obtain IC50 value and Hill number (n) for each compound. Testing at least 10 different inhibitor concentrations is preferred. Results are presented below in Table I. Table I (TableRemoved) Results and Discussion: As can be seen from the data shown in Table I, the compounds of the invention are effective inhibitors of BACE1. WE CLAIM: 1. A compound of formula I (Formula Removed) wherein R1and R2 are each independently H or an optionally substituted C1-C4alkyl group; R3 and R4 are each independently H, or an optionally substituted C1-C4 alkyl group or R3 and R4 may be taken together to form a 4- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; R5, R6 and R7 are each independently H, halogen, NO2, CN, OR11, NR12R13 or a C1-C6alkyl, C1-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl C3-C8cycloalkyl, cycloheteroalkyl, aryl or aryl(C1-C4)alkyl group each optionally substituted or when attached to adjacent carbon atoms R5 and R6 may be taken together with the atoms to which they are attached to form an optionally substituted 5- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; R8, R9 and R10 are each independently H, halogen, NO2, CN, OR14, NR15R16 or a C1-C6alkyl, C1-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C8cycloalkyl, cycloheteroalkyl, aryl or aryl(CrC4)alkyl group each optionally substituted or when attached to adjacent carbon atoms RS and R9 may be taken together with the atoms to which they are attached to form an optionally substituted 5- to 7-membered ring optionally containing one or two heteroatoms selected from O, N or S; n is 0, 1 or 2; R11 and R14 are each independently H or a C1-C6alkyl, C1-C6haloalkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C8cycloalkyl or aryl group each optionally substituted; and Ri2, Ria, RIS and R16 are each independently H, C1-C4alkyl, C3-C8cycloalkyl or R12 and R13 or R15 or R16 may be taken together with the atom to which they are attached to form a 5- to 7-membered ring optionally containing an additional heteroatom selected from O, N or S; or a tautomer thereof, a stereoisomer thereof or a pharmaceutically acceptable salt thereof. 2. A compound according to claim 1 wherein R-\ and R2 are H. 3. A compound according to claim 1 or claim 2 wherein R5 is a C1-C6alkyl, C1-C6alkoxy, Cr6haloalkyl or benzyl group each optionally substituted. 4. A compound according to claim 3 wherein R5 is t-butyl, CF3, C1-C3alkoxy or an optionally substituted benzyl group. 5. A compound according to any one of claims 1 to 4 wherein R8 is hydrogen, C1-C6alkyl, C1-C6alkoxy, C1-6haloalkyl or benzyl group each optionally substituted. 6. A compound according to any one of claims 1 to 4 wherein R8 is H or C1-C3 alkoxy. 7. A compound according to any one of claims 1 to 5 wherein R9 is H or C1 C3alkyl. 8. A compound according to any one of claims 1 to 7 wherein R6, R7 and RIO are H. 9. A compound according to any one of claims 1 to 8 wherein n is 1. 10. A compound according to any one of claims 1 to 8 wherein n is 0. 11. A compound according to any one of claims 1 to 10 wherein R3 and R4 are independently H or methyl. 12. A compound according to any one of claims 1 to 10 wherein R3 and R4 are both H. 13. The compound according to claim 1 selected from the group consisting of: 8-(4-tert-butylphenyl)-8-phenyl-2,3,4,8-tetrahydroimidazol[1, 5-a]pyrimidin-6-amine; 8-(3-benzylphenyl)-8-phenyl-2,3,4,8-tetrahydroimidazol[1,5-a]pyrimidin-6-amine; 8-[3-(4-fluorophenoxy)phenyl]-8-phenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8-[3-(4-methoxybenzyl)phenyl]-8-phenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8-[3-(4-fluorobenzyl)phenyl]-8-phenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8-phenyl-8-[3-(trifluoromethyl)phenyl]-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8-(3-methoxyphenyl)-8-phenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 7-(4-methoxy-3-methylphenyl)-7-(3-propoxyphenyl)-2,7-dihydro-3H-imidazo[1,5-a]imidazol-5-amine; 8-(4-methoxy-3-methylphenyl)-8-(3-propoxyphenyl)-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8-(4-methoxy-3-methylphenyl)-3,3-dimethyl-8-(3-propoxyphenyl)-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8,8-diphenyl-2,3,4,8-tetrahydroimidazo[1,5-a]pyrimidin-6-amine; 8-[3-(2-cyclopropyl-ethyl)-phenyl]-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro- imidazo[1,5-a]pyrimidin-6-ylamine; 8-(3-allylphenyl)-8-(4-trifluoromethoxyphenyl)-2,3,4,8-tetrahydro-imidazo[1,5- a]pyrimidin-6-ylamine; 8-(3-propyl-phenyl)-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5- a]pyrimidin-6-ylamine; 3-[6-amino-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5-a]pyrimidin-8- yl]-N-ethyl-benzamide; N-{3-[6-amino-8-(4-trifluoromethoxy-phenyl)-2,3,4,8-tetrahydro-imidazo[1,5-a]pyrimidin-8-yl]-phenyl}-propionamide hydrochloride; a tautomer thereof; a stereoisomer thereof; and a pharmaceutically acceptable salt thereof. 14. A method for the treatment of a disease or disorder associated with excessive BACE activity in a patient in need thereof which comprises providing said patient an effective amount of a compound of any one of claims 1 to 13. 15. The method according to claim 14 wherein said disease or disorder is Alzheimer's disease, cognitive impairment, Down's Syndrome, HCHWA-D, cognitive decline, senile dementia, cerebral amyloid angiopathy, degenerative dementia, or a neurodegenerative disorder. 16. A pharmaceutical composition which comprises a pharmaceutically acceptable carrier and an effective amount of a compound of formula I as claimed in any one of claims 1 to 13, a tautomer thereof, a stereoisomer thereof or a pharmaceutically acceptable salt thereof. 17. The invention substantially such as herein described.