Claims:We Claim:
1. 4-(4-Methyl phenoxy) benzyl phenyl urea having plant growth regulating activity and the Formula I:

Formula I
and acid addition salt thereof.

2. A process for the synthesis of 4-(4-methyl phenoxy) benzyl phenyl urea having plant growth regulating activity and the Formula I:

Formula I
by condensing phenyl isocyanate of the Formula II:

Formula II

with 4-(4-methyl phenoxy) benzyl amine of the Formula III:

Formula III

in the molar ratio 1:1-1.12 in an organic solvent at 25to120 OC and isolating the 4-(4-methyl phenoxy) benzyl phenyl urea from the reaction and if desired, converting the product into acid addition salt thereof.

3. The process as claimed in claim 2, wherein the solvent is selected from aromatic hydrocarbon, halogenated aromatic hydrocarbon or halogenated aliphatic hydrocarbon.

4. The process as claimed in claim 3, wherein the aromatic hydrocarbon is selected from benzene, toluene and xylene.

5. The process as claimed in claim 3, wherein the halogenated aromatic hydrocarbon is selected from chlorobenzene, such as monochloro benzene.

6. The process as claimed in claim 3, wherein the halogenated aliphatic hydrocarbon is selected from dichloromethane and chloroform.

7. The process as claimed in any one of claims 3 - 6, wherein the solvent includes additional solvents selected from dimethyl foranamide, dimethylacetamide and diisopropylethyl amine.

8. The process as claimed in claim 2, which is carried out in the presence of a phase transfer catalyst.

9. The process as claimed in claim 8, wherein the phase transfer catalyst is selected from benzyl triethyl ammonium chloride, tetra butyl ammonium bromide and tetrabutyl ammonium chloride.

10. A growth promoting composition for agricultural and horticultural crops comprising 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula I:

Formula I
and an acid addition salt thereof, in an effective growth regulating amount, together with an anionic and/or nonionic emulsifier surfactant and a solvent.

11. The composition as claimed in claim 10, comprising 4-(4-methyl phenoxy) benzyl phenyl urea in an effective amount of 0.04 - 0.1% w/w.

12. A method of controlling growth in agricultural and horticultural crops by contacting plant with 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula 1:

Formula I
and acid addition salt thereof, in an effective growth regulating amount.

13. The method as claimed in claim 12, wherein the 4-(4-methyl phenoxy) benzyl phenyl urea is in an effective amount of 0.04 - 0.1% w/w.

14. A method of controlling growth in agricultural and horticultural crops by contacting plant with a growth promoting composition comprising 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula 1:

Formula I
and acid addition salt thereof, in an effective growth regulating amount, in combination with an anionic and/or nonionic emulsifier surfactant and a solvent.

15. The method claim 14, wherein the 4-(4-methyl phenoxy) benzyl phenyl urea is in an effective amount of 0.04 - 0.1% w/w.

16. Use of 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula I:

Formula I
and acid addition salt thereof in an effective growth regulating amount for controlling growth activity in agricultural and horticultural crops.

17. Use as claimed in claim 16, wherein the 4-(4-methyl phenoxy) benzyl phenyl urea in an effective amount of 0.04 - 0.1% w/w.

18. Use of 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula 1:

Formula I
and acid addition salt thereof, in an effective growth regulating amount, in combination with an anionic and/or nonionic emulsifier surfactant and a solvent for controlling growth activity in agricultural and horticultural crops.

19. Use as claimed in claim 18, wherein the 4-(4-methyl phenoxy) benzyl phenyl urea is in an effective amount of 0.04 - 0.1% w/w.

Dated this 16th day of December 2015
, Description:FIELD OF THE INVENTION
This invention relates to 4-(4-methyl phenoxy) benzyl phenyl urea having plant growth regulating activity and process for the synthesis thereof.

This invention also relates to growth regulating composition comprising 4-(4-methylphenoxy) benzyl phenyl for agricultural and horticultural crops, use of the same for regulation of plant growth and method of regulating plant growth with the same.

The 4-(4-methylphenoxy)benzyl phenyl urea of the invention has the following structural Formula I:

Formula I

BACKGROUND OF THE INVENTION
With the increasing population, shortage of food and other agricultural and horticultural produce is a matter of grave concern globally. Therefore, efforts are on to find ways to increase agricultural and horticultural production. Control or regulation (acceleration or suppression) of plant growth with plant growth regulators or promoters is one of the major techniques used in the agricultural and horticultural industry to increase agricultural and horticultural output. Extensive research and development activities are being carried world over to find ways to improve agricultural and horticultural productivity and to develop new compounds having plant growth promoting or regulating activity for improving agricultural and horticultural productivity.

Insecticidal derivatives of diphenyl urea and their synthesis by reacting isocyanates having different substituents with amines are reported (US 2745874). Diphenyl ureas having use as colourants, antioxidants, perfumes, water softeners, emollients and the like are reported to be prepared from anilines (US2894986). N- aryl – N’- amino alkyl ureas having anaesthetic action and their synthesis by the reaction of substituted phenyl isocyanate with different amino alkyls are reported (GB 736630). Preservation of plant materials by treatment with urea derivatives is reported (GB 1122662). Synthesis of isocyanates and their use for preparation of different compounds such as insecticides, coatings and adhesives, elastomers or foams are reported (US 3345395 and 4477389).

It is reported (US 4193788) that novel 4-pyridylureas and thioureas containing a chlorine atom in the 2-position of the pyridine ring and having plant regulating activity is prepared from phenyl isocyanate of the Formula II:

Formula - II

It is also reported (CN 102863356B, US 5039693) that pesticides such as tolfenpyrard is synthesized with 4-(4-methylphenoxy) benzylamine of the Formula III:

Formula III

Because of the ever growing demand for increasing agricultural and horticultural productivity, there is, however, still a continuing need and demand for developing new compounds having plant growth regulating activity and methods for synthesis thereof and methods for controlling plant growth.

DESCRIPTION OF THE INVENTION
In our efforts to synthesis new compounds having plant growth regulating activity we have found out by extensive research and experimentation that compound of the Formula I can be synthesized by reacting phenyl isocyanate of the Formula II

Formula - II

with 4-(4-methyl phenoxy) benzylamine of the Formula III

Formula III

A distinctive feature of the compound of Formula I is that it has a methyl group at the 4-positon of the phenoxy group and the phenoxy methyl group is attached to the 4-position of the benzyl amine. The compound of the Formula I comprising the phenoxy methoxy group at the 4-position of the benzyl amine is new having regard to the characterization studies carried out by us and the prior art. The compound of the Formula I has also been found to have plant growth regulating activity based on the activity studies carried out by us.

It is quite clear from the prior art that there is no explicit or implied suggestion in the prior art that compound of the Formula I having a methyl group at the 4 -position of the phenoxy group and the phenoxy methyl group attached to the 4 -position of the benzyl amine and having plant regulating activity can be synthesized by reacting compounds of the formulae II and III as stated herein below. Therefore, there is no teaching towards the compound of the Formula I and its activity and synthesis in the prior art for a person skilled in the art to be prompted or motivated to work towards the compound of the Formula I and its activity and synthesis and the compound of the Formula I and its synthesis and activity studies constitute a patentable invention.
According to the invention there is thus provided 4-(4-methyl phenoxy) benzyl phenyl urea having plant growth regulating activity and the Formula I:

Formula I
and acid addition salt thereof.

According to the invention there is also provided a process for the synthesis of 4-(4-methyl phenoxy) benzyl phenyl urea having plant growth regulating activity and the Formula I:

Formula I

by condensing phenyl isocyanate of the Formula II:

Formula II

with 4-(4-methyl phenoxy) benzyl amine of the Formula III:

Formula III

in the molar ratio 1:1-1.12 in an organic solvent at 25 to 120 0C and isolating the 4-(4-methyl phenoxy) benzyl phenyl urea from the reaction and if desired, converting the product into acid addition salts thereof.

The solvent used for the condensation reaction between compounds of Formulae II and III is selected from aromatic hydrocarbon, halogenated aromatic hydrocarbon or halogenated aliphatic hydrocarbon. The aromatic hydrocarbon is selected from benzene, toluene and xylene. The hydrogenated aromatic hydrocarbon is selected from chlorobenzene, such as monochloro benzene. The halogenated aliphatic hydrocarbon is selected from dichloromethane and chloroform. The solvent can be mixture of solvents and can include additional solvents selected from dimethyl formamide, dimethylacetamide and diisopropylethyl amine.

The process is advantagously carried out in the presence of a phase transfer catalyst selected from benzyl triethyl ammonium chloride, tetra butyl ammonium bromide and tetrabutyl ammonium chloride to improve conversion into and yield of compound of the Formula I.

According to the invention there is also provided a growth promoting composition for agricultural and horticultural crops comprising 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula I:

Formula I

and an acid addition salt thereof, in an effective growth regulating amount, together with an anionic and/or nonionic emulsifier surfactant and a solvent.

According to the invention there is also provided a method of controlling growth in agricultural and horticultural crops by contacting plant with 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula 1:

Formula I

and acid addition salt thereof, in an effective growth regulating amount.

According to the invention there is also provided a method of controlling growth in agricultural and horticultural crops by contacting plant with a growth promoting composition comprising 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula 1:

Formula I
and acid addition salt thereof, in an effective growth regulating amount, in combination with an anionic and/or nonionic emulsifier surfactant and a solvent.

According to the invention there is also provided use of 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula I:

Formula I
and acid addition salt thereof in an effective growth regulating amount for controlling growth activity in agricultural and horticultural crops.

According to the invention there is also provided use of 4-(4-methyl phenoxy) benzyl phenyl urea of the Formula 1:

Formula I
and acid addition salt thereof, in an effective growth regulating amount, in combination with an anionic and/or nonionic emulsifier surfactant and a solvent for controlling growth activity in agricultural and horticultural crops.

The 4-(4-methyl phenoxy) benzyl phenyl urea is, preferably in an effective growth regulating amount of 0.04 - 0.1% w/w.

The anionic and/or nonionic emulsifier surfactants used with the compound of the Formula I can be one or more selected from ammonium lauryl sulfate, sodium lauryl sulfate and related alkyl-ether sulfates sodium laureth sulfate, also known as sodium lauryl ether sulfate (SLES), and dioctyl sodium sulfosuccinate, linear alkylbenzene sulfonates (LABs), fatty vegetable oil ethoxylated , glycerol alkyl esters, glyceryl laurate, polyoxyethylene glycol, sorbitan alkyl esters, polysorbate, cocamide methyl amine, cocamide diethylamine and dodecyldimethylamine oxide.

The solvent used with the compound of the Formula I is a non-ester ether – based solvent and can be one or more solvents selected from water ,ethylene glycol, propylene glycol, ketones, dimethylforamide, N- methyl -2-pyrolidine, aliphatic alcohol such as ethyl alcohol, isopropyl alcohol or n-Butanol or mixed polar solvent, aromatic hydrocarbon such as toluene, C-9 and C-10 solvents.

The compound of the Formul1 I is converted into its acid addition salt, if required, by treating the compound with acids such as hydrochloric acid, sulfuric acid or acetic acid to form chlorides, sulphates or acetates, respectively.

The following examples are illustrative of the invention but not limitative of the scope thereof

Working Example 1
To methane dichloride (MDC) (100 ml) and 4-(4-methylphenoxy) benzyl amine (8.9 gm, 0.041 gm- mol), phenyl isocyanate (4.9 gm, 0.041 gm- mol) was added in 1.5 hrs by maintaining the reaction at 25 - 30 OC under-stirring. Following this, the reaction was maintained at 25 – 30 OC for 4 hrs under stirring.
MDC was distilled out under reduced pressure and recovered. Residue was filtered to separate crude 4-(4-methyl phenoxy) benzyl phenyl urea.
Crude product was dissolved in hot ethanol (50 ml) at 50 OC and activated charcoal 0.01 gm was added and stirred for 0.5 hr. The mixture was filtered, ethanol concentrate was cooled to 5 OC and maintained at that temperature for 2.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.036 gm- mole, >97.0% , overall yield 87.80%.

Working Example 2
To chloroform (100 ml) and 4-(4-methylphenoxy) benzyl amine (8.9 gm, 0.041 gm- mol), phenyl isocyanate (5.5 gm, 0.046 gm-mol) was added in 1.5 hrs by maintaining the reaction at 25 – 30 OC under stirring. Following this, the reaction was maintained at 25 to 30 OC for 10 hrs under stirring.
Chloroform was distilled out under vacuum and recovered. Residue was filtered to separate crude 4-(4-methyl phenoxy) benzyl urea.
Crude product was dissolved in hot methanol (50 ml) at 50 OC and activated charcoal (0.01 gm) was added and stirred for 0.5 hr. The mixture was filtered, methanol concentrate was cooled to 5 OC and maintained at that temperature for 5.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.037 gm- mole, >97.0%, overall yield 90.24%.

Working Example 3
To toluene (100 ml), 4-(4-methylphenoxy) benzyl amine, (8.9 gm, 0.041 gm -mol) and benzyl triethyl ammonium chloride (0.01 gm), phenyl isocyanate (4.9 gm, 0.041 gm- mol) was added in 1.5 hrs under stirring by maintaining the reaction at 100 – 105 OC. Following this, the reaction was maintained at 100 OC for 4 hrs under stirring.

Toluene was distilled under reduced pressure and recovered. Residue was cooled to 25 – 30 OC and filtered to separate crude 4-(4-methyl phenoxy) benzyl phenyl urea.

Crude product was dissolved in hot ethanol (50 ml) at 50 OC and activated charcoal (0.01 gm) was added and stirred for 0.5 hr. The mixture was filtered, ethanol concentrate was cooled to 5 OC and maintained at that temperature for 2.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.037 gm- mole, >97.0% , overall yield 90.24%.

Working Example 4
To methane dichloride (MDC) (100 ml), 4-(4-methylphenoxy) benzyl amine (8.9 gm, 0.041 gm-mol) and tetrabutyl ammonium chloride (0.01 gm), phenyl isocyanate (4.9 gm, 0.041 gm-mol) was added in 1.5 hrs under stirring by maintaining the reaction at 25 – 30 OC. Following this, the reaction was maintained at 25 to 30 OC for 4 hrs under stirring.
MDC was distilled out under reduced pressure and recovered. Residue was filtered to separate out crude 4-(4-methyl phenoxy) benzyl phenyl urea.
Crude product was dissolved in hot ethanol (50 ml) at 50 OC and activated charcoal (0.01 gm) was added and stirred for 0.5 hr. The mixture was filtered, ethanol concentrate was cooled to 5 OC and maintained at that temperature for 2.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.037 gm-mole, >97.0%, overall yield 90.24%.

Working Example 5
To monochloro benzene 100 ml, 4-(4-methylphenoxy) benzyl amine (8.9 gm, 0.041 gm-mol) and benzyl triethyl ammonium chloride (0.01 gm), phenyl isocyanate (4.9 gm, 0.041 gm-mol) was added in 1.5 hrs under stirring by maintaining the reaction at 110 – 115 OC. Following this, the reaction was maintained at 110 OC for 4 hrs under stirring.

Monochloro benzene was distilled out under reduced pressure and recovered. Residue was cooled to 25-30 OC and filtered to separate out crude 4-(4-methyl phenoxy) benzyl phenyl urea.

Crude product was dissolved in hot ethanol (50 ml) at 50 OC and activated charcoal (0.01 gm) was added and stirred for 0.5 hr. The mixture was filtered, methanol concentrate was cooled to 5 OC and maintained at that temperature for 2.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.037 gm- mole, >97.0% , over all yield 90.24%.

Working Example 6
To xylene (120 ml) and 4-(4-methylphenoxy) benzyl amine (8.9 gm, 0.041 gm- mol), phenyl isocyanate (4.9 gm, 0.041 gm-mol) was added in 1.5 hrs under stirring by maintaining the reaction at 120 OC. Following this, the reaction was maintained at 120 OC for 3 hrs under stirring.
Xylene was distilled out under reduced pressure and recovered. Residue was cooled to 25-30 OC and filtered to separate out crude 4-(4-methyl phenoxy) benzyl phenyl urea.
Crude product was dissolved in hot isopropyl alcohol (50 ml) at 50 OC and activated charcoal (0.01 gm) was added and stirred for 0.5 hr. The mixture was filtered, ethanol concentrate was cooled to 5 OC and maintained at that temperature for 2.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.036 5gm- mole, >97.0% , overall yield 89.02%.

Working Example 7
To methane dichloride (MDC) (100 ml), 4-(4-methylphenoxy) benzyl amine (8.9 gm, 0.041 gm- mol) and triethyl amine (0.2 gm), phenyl isocyanate (4.9 gm, 0.041 gm- mol) was added in 1.5 hrs under stirring by maintaining the reaction at 25-30 OC. Following this, the reaction was maintained at 25.0 to 30.0 OC for 4 hrs under stirring.
MDC was distilled out under reduced pressure and recovered. Residue was filtered to separate crude 4-(4-methyl phenoxy) benzyl phenyl urea.

Crude product was dissolved in hot ethanol (50 ml) at 50 OC and activated charcoal (0.01 gm) was added and stirred for 0.5 hr. The mixture was filtered, ethanol concentrate was cooled to 5 OC and maintained at that temperature for 2.0 hrs and then filtered. Product was dried under vacuum for 3.0 hrs at 50 OC to obtain 0.036gm-mole, >97.0% , overall yield 87.8%.

Characterization Example
4-(4-Methyl phenoxy) benzyl phenyl urea obtained by the procedures of Working Examples (Experimental Examples or Preparation Examples) 1 to 7 was analyzed and the structure of Formula 1 was confirmed by instrumental analysis as follows:
Molecular formula : C21H20O2N2

NMR Data
2.27 ( s, 3H) ; 4.26- 4.27 ( d, 2H) ; 6.57 ( s, 1H) ; 6.6 – 7.41 ( m, 13H) ; 8.5 (s, 1H)

IR Data ( cm-1)
3329 ( -NH), 1644 ( -C=O) , 1500 ( - CNH) ,1312 ( - C-N)

LCMC Data
( m+1) :332.9

Melting point : 126 – 128ºC

Formulation Example 1A
An emulsifiable concentrate of 4-(4-methyl phenoxy) benzyl phenyl urea obtained by Example 1 was prepared by mixing the 4-(4-methyl phenoxy) benzyl phenyl urea (0.04 parts by weight) with isopropyl alcohol (94.96 parts) and anionic surfactant poly-20 (2.5 parts by weight) and non-ionic surfactant unisatb10 M (2.5 parts by weight) of Unitop (India) Pvt. Ltd, Mumbai. The emulsiable concentrate was diluted with water so as to form 4 Test Solutions of concentrations of 0.25 ppm, 0.50 ppm, 0.75 ppm and 1.0 ppm, respectively. The Test Solutions were applied on crops as follows:

Test Example 1 A
Okra was grown on an outdoor farm in a conventional manner. Foliar applications of the Test Solutions were imposed in an amount of 5 liters per 100 square meters of cultivation area 30 days after sowing. Fruits from 15 plants were harvested from each test plot including untreated plot. The weight of harvested fruits of each plant was weighed to determine the average fruit weight per plant and calculate the relative value (%) to non - treated test plot. The results were as shown in the following Test Table 1.

Test Table 1
Test Solutions Concentration of
Test Solutions
(ppm) Relative Yield %
(Fruit wt/plant)
1 0.25 123.5
2 0.50 130.2
3 0.75 144.8
4 1.00 147.9

Test Example 2 A
Tomato was grown on an outdoor farm in a conventional manner. Foliar applications of the Test Solutions were imposed in an amount of 5 liters per 100 square meters of cultivation area 30 days after sowing. Fruits from 15 plants were harvested from each test plot including untreated plot. The weight of harvested fruits of each plant was weighed to determine the average fruit weight per plant and calculate the relative value (%) to non - treated test plot. The results were as shown in the following Test Table2.
Test Table 2
Test Solutions Concentration of Test Solutions
(ppm) Relative Yield %
(Fruit wt/plant)
1 0.25 111.6
2 0.50 116.4
3 0.75 134.3
4 1.00 146.9

Test Example 3 A
Maize was grown on an outdoor farm in a conventional manner. Foliar applications of the Test Solutions were imposed in an amount of 5 liters per 100 square meters of cultivation area 45 days after sowing. Cobs from 15 plants were harvested from each test plot including untreated plot. The weight of harvested cobs of each plant was weighed to determine the average fruit weight per plant and calculate the relative value (%) to non - treated test plot. The results were as shown in the following Test Table 3.

Test Table 3
Test Solutions Concentration of Test Solutions
(ppm) Relative Yield %
(Cob wt/plant)
1 0.25 113.9
2 0.50 119.0
3 0.75 123.9
4 1.00 124.9

Test Example 4 A
Soybean was grown on an outdoor farm in a conventional manner. Foliar applications of the Test Solutions were imposed in an amount of 5 liters per 100 square meters of cultivation area 45 days after sowing. Pods from 15 plants were harvested from each test plot including untreated plot. The weight of harvested pods of each plant was weighed to determine the average fruit weight per plant and calculate the relative value (%) to non - treated test plot. The results were as shown in the following Test Table 4.

Test Table 4
Test Solutions Concentration of Test Solutions
(ppm) Relative Yield %
(Pod wt/plant)
1 0.25 112.8
2 0.50 122.9
3 0.75 126.9
4 1.00 144.0

Test Example 5 A
Potato was grown on an outdoor farm in a conventional manner. Foliar applications of Test Solutions were imposed in an amount of 5 liters per 100 square meters of cultivation area 30 days after sowing. 75 days after setting, 15 plants of good growth and development were dug out from each test plot including untreated plot, and the average weight of potato tubers was measured to determine the average potato weight per plant and calculate its relative value (%) to non-treated test plot. The results were as shown in the following Test Table 5.

Table 5
Test Solutions Concentration of Test Solutions
(ppm) Relative Yield %
(Tuber wt./plant)
1 0.25 108.9
2 0.50 113.7
3 0.75 121.9
4 1.00 131.9

It is quite clear from the Tables that yield of crops treated with the composition of the invention in concentrations of 0.25 to 1.0 ppm of the active compound of the Formula I increased as compared to the non-treated crops thereby establishing the plant growth regulating activity of the compound of the Formula I and its usefulness in agriculture and horticulture to increase yield.