DESC:Field of the Invention
The present invention relates to an improved and industrially advantageous process for the preparation of Trifloxystrobin of formula I and intermediates thereof. The process is simple, cost-effective, efficient and commercially viable.

Background of the Invention
Trifloxystrobin having IUPAC name methyl (E)-methoxyimino-{(E)-a-[1-(a,a,a-trifluoro-m-tolyl) ethylideneaminooxy]-o-tolyl}acetate as represented by formula I belongs to the group of Strobilurin class of fungicides. It is an important commercial fungicide in agriculture.

A number of processes for the preparation of Trifloxystrobin and intermediates are reported in the literature. However these literature processes are suffered one or more drawbacks and necessitates to develop an improved process for the preparation of Trifloxystrobin and intermediates thereof using improved process steps and cost effective reagents.

Object of the Invention
It is the foremost object of the present invention to provide industrially advantageous and cost-effective process for the preparation of Trifloxystrobin.

Yet other object of the present invention is to provide a process for the preparation of Trifloxystrobin by using simple, economical and commercially viable reagents and process steps via intermediate methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino)acetate.

Yet another object of the present invention is to provide an simple, efficient, cost effective, commercially viable improved process for the preparation of intermediate methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino)acetate.

Summary of the Invention
Accordingly, the present invention provides an improved and industrially advantageous process for the preparation of Trifloxystrobin of formula I

Formula I
which comprises the steps of:
a) brominating the compound of formula II in presence of Lewis acid catalyst in a suitable solvent

Formula II
to form compound of formula III

Formula III
b) purifying the obtained compound of formula III using suitable solvent,
c) oximation of the compound of formula IV, using improved process

Formula IV
to form compound of formula V

Formula V
d) coupling the compound of formula III and compound of formula V, using catalyst in a suitable solvent to form compound of formula I.

According to one other embodiment, the present invention provides a simple, efficient, cost effective, commercially viable improved process for preparation of compound of formula III, a key intermediate for the preparation of Trifloxystrobin of formula I by brominating the compound of formula II using bromine solution as a brominating agent in presence of Lewis acid catalyst in a suitable solvent and purifying the obtained compound using suitable solvent.

According to one other embodiment, the present invention provides a simple, efficient, cost effective, commercially viable improved process for preparation of compound of formula V, a key intermediate for the preparation of Trifloxystrobin of formula I by oximising the compound of formula IV by adding hydroxylamine hydrochloride in two lots and extracting the compound of formula V using suitable solvents to enable its use directly in next anhydrous step.

According to one other embodiment, the present invention provides a simple, efficient, cost effective, commercially viable improved process for preparation of compound of formula I, by coupling the intermediate III and V using catalyst TEBAC (Triethyl benzyl ammonium chloride) and obtain the compound in high yield, high purity and in lesser time.

Detailed description of the Invention
The definitions provided herein for the terminologies used in the present disclosure are for illustrative purpose only and in no manner limit the scope of the present invention disclosed in the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the invention pertains. Although other methods and materials similar, or equivalent, to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.

It is to be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

As used herein, the terms "comprises", "comprising", "includes", "including", or any other variation thereof, are intended to cover a non-exclusive inclusion, subject to any limitation explicitly indicated.
Accordingly, the present invention provides an improved and industrially advantageous process for the preparation of Trifloxystrobin of formula I

Formula I
which comprises the steps of:
a) brominating the compound of formula II in presence of Lewis acid catalyst in a suitable solvent

Formula II
to form compound of formula III,

Formula III

b) purifying the obtained compound of formula III using suitable solvent,
c) oximation of the compound of formula IV, using improved process

Formula IV
to form compound of formula V

Formula V
d) coupling the compound of formula III and compound of formula V, using catalyst in a suitable solvent to form compound of formula I.

The brominating agent used in step a) is bromine solution in suitable solvent selected from dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof.

The Lewis acid used in step a) is selected from ZnCl2, FeCl3, AlCl3 or TiCl4.

The suitable solvent used in step a) is selected from chlorinated solvent such as dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof.

The suitable purification solvent used in step b) is selected from methyl cyclohexane, cyclohexane or mixtures thereof.

In step c) compound of formula IV is undergo oximation using reagent hydroxylamine hydrochloride which is added in two lots and in lesser quantity to obtain the compound of formula V.

In step c) compound of formula V is extracted using a suitable hydrocarbon solvent such as toluene, xylene or mixtures thereof to enable its use directly in next anhydrous step.

In step d) the coupling of compound of formula III and formula V is carried out in presence of catalyst TEBAC (Triethyl benzyl ammonium chloride).

The suitable solvent used in step d) is selected from acetone, acetonitrile, propionitrile, methyl ethyl ketone, methyl isobutyl ketone, xylene, toluene or mixtures thereof.

According to one other embodiment, the present invention provides a simple, efficient, cost effective, commercially viable improved process for preparation of compound of formula III, a key intermediate for the preparation of Trifloxystrobin of formula I by brominating the compound of formula II using bromine solution as a brominating agent in presence of Lewis acid catalyst such as ZnCl2, FeCl3, AlCl3 or TiCl4 in a suitable solvent dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof and purifying the obtained compound of formula III using suitable solvent such as methyl cyclohexane, cyclohexane or mixtures thereof.
According to one other embodiment, the present invention provides a simple, efficient, cost effective, commercially viable improved process for preparation of compound of formula V, a key intermediate for the preparation of Trifloxystrobin of formula I by oximising the compound of formula IV by adding hydroxylamine hydrochloride in two lots and extracting the compound of formula V using suitable solvents to enable its use directly in next anhydrous step.

According to one other embodiment, the present invention provides a simple, efficient, cost effective, commercially viable improved process for preparation of compound of formula I, by coupling the intermediate III and V using catalyst TEBAC (Triethyl benzyl ammonium chloride) and obtain the compound in high yield, high purity and in lesser time.

The process steps described here such as a) to d) can be performed individually or may be performed in in-situ manner.

Starting compound of formula II and IV can be prepared by the methods known in art or can be procured from market.

The intermediate described here in the present invention include their salts, hydrates, solvates, racemates, enantiomers, polymorphs etc.

Generally, the reaction at different stages to prepare compounds of formulae I, III and V can be performed at a suitable temperature ranging from 0 °C to reflux temperature of solvent used for specific reaction for few minutes to few hours or till completion of reaction. A detailed explanation of which are set out in examples given below.

The order and manner of combining the reactants at any stage of the process are not critical and may be varied. The reactants may be added to the reaction mixture as solids, or may be dissolved individually and combined as solutions. A detailed explanation of which are set out in examples given below.

The process according to the present invention has the following advantages over the known prior arts,
• The process of the present invention is industrially advantageous, simple, efficient, cost effective and commercially viable due to use of cost-effective reagents, catalysts and process steps.
• The process of the present invention uses the much safer catalyst FeCl3, ZnCl2, AlCl3 or TiCl4 for bromination step compared to prior art catalyst Azobisisobutyronitrile (AIBN), Benzyl peroxide, 1-Ethyl-3-(3'-dimethylaminopropyl) carbodiimide hydrochloride.
• The process of the present invention uses the less amount of hydroxylamine hydrochloride hence environment friendly.
• The process of the present invention uses hydrocarbon solvent for extraction of intermediate of formula V which enable its use in next anhydrous step successfully.
• The process of the present invention uses the less amount of solvents in all reaction steps hence environment friendly.
• The process of the present invention requires the minimum operations which is economical and efficient on a commercial scale.
• The process of the present invention provides compound of formula I in high purity and high yield.

Having described the invention with reference to certain preferred aspects, other aspects will become apparent to one skilled in the art from consideration of the specification. The invention is further defined by reference to the following examples describing in detail by the preparation of the compounds of the invention.

Examples
Preparation of methyl (E)-2-(2-(bromomethyl) phenyl)-2-(methoxyimino) acetate
Example 1:
73 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 290 gm dichloromethane is stirred for 5-10 minutes followed by adding 11.42 gm FeCl3 and 87.6 gm water at temperature 20-30 oC, stirred for 15 minutes followed by cooling to temperature 10 to 15 °C and added bromine solution (62 gm bromine in 193 gm dichloromethane) at temperature 10-15 oC, stirring at temperature 20-25 °C to get complete product formation, checked by HPLC, added 109.5 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 109.5 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation. Organic layer washed with 109.5 gm water stirred, settle and separate layer at room temperature, take organic layer and added 146 gm water and adjust the pH 6-7 with caustic lye, stirred and layer separated. Distilled out dichloromethane and added 146 gm methyl cyclohexane, stirred at temperature 50-55 oC to get dissolved followed by cooling to complete crystallization at temperature 10-15 oC, filtered the mass and washed with methyl cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 80 gm (79.4%) with HPLC purity 97.5%.

Example 2:
70 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 277 gm dichloromethane is stirred for 5-10 minutes followed by adding 10.94 gm FeCl3 and 84 gm water at temperature 20-25 oC, then stirred for 15 minutes followed by cooling to temperature 10 to 15 °C and adding bromine solution (59.35 gm bromine in 185 gm dichloromethane) at 10-15 oC, stirring at temperature 20-25 °C to get complete product formation, checked by HPLC, added 70 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 70gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, Organic layer washed with 140 gm water, stirred, settle and separate layer at room temperature. Take organic layer and added 140 gm water and adjust the pH 6-7 with caustic lye, stirred and layer separated. Distilled out dichloromethane and added 183 gm methyl cyclohexane stirred at temperature 50-55 oC to get dissolved followed by cooling to complete crystallization at temperature 10-15 oC, filtered the mass and washed with methyl cyclohexane to get methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 73.7 gm (76.3%) with HPLC purity 98.49%.

Example 3:
50 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 198 gm dichloromethane is stirred, followed by adding 6.57 gm ZnCl2 and stirred for 15 minutes, then added 30 gm water at temperature 20-30 oC and stirred for 30 min followed by cooling to 10-15 °C and adding bromine solution (38.54 gm bromine in 132 gm dichloromethane) at 10-15 oC in 1.5 hours, stirring at temperature 20-25 °C to get complete product formation, checked by HPLC, added 75 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation. Take organic layer and added 75 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation. Organic layer washed with 100 gm water, stirred, settle and separate layer at room temperature. Take organic layer and added 100 gm water and adjust the pH 6-7 with caustic lye, stirred and layer separated. Distilled out dichloromethane followed by adding 154 gm methyl cyclohexane, stirred at temperature 50-55 oC to get dissolved followed by cooling to complete crystallization at temperature 10-15 oC filtered the mass and washed with methyl cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 55.9 gm (81%) with HPLC purity 95.68%.

Example 4:
500 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 1980 gm dichloromethane is stirred for 5-10 minutes followed by adding 78.26 gm FeCl3 and 1500 gm water at temperature 20-30 oC, then stirred for 15 minutes followed by cooling to 10-15 °C and added bromine solution (424 gm bromine in 1320 gm dichloromethane) at 10-15 oC, stirring at temperature 20-25 °C to get complete product formation, checked by HPLC, added 750 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 750 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, organic layer washed with 1000 gm water, stirred, settle and separate the layer at room temperature. Take organic layer and added 1000 gm water and adjust the pH 6-7 with caustic lye stirring and layer separated. Distilled out dichloromethane then added 1155 gm methyl cyclohexane, stirred at temperature 50-55 oC to get dissolved followed by cooling to complete crystallization at temperature 10-15 oC, filtered the mass and washed with methyl cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 585.5 gm (84.85%) with HPLC purity 97.11%.

Example 5:
500 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 1980 gm dichloromethane is stirred for 5-10 minutes followed by adding 78.26 gm FeCl3 and 600 gm water at temperature 20-30 oC, then stirred for 15 minute followed by cooling to 10-15 °C and added bromine solution (424 gm bromine in 1320 gm dichloromethane) at 10-15 oC, stirring at temperature 20-25 °C to get complete product formation, checked by HPLC, added 750 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 750 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, organic layer washed with water, stirred, settle and separate layer at room temperature. Take organic layer and added 1000 gm water and adjust the pH 6-7 with caustic lye stirred and layer separated. Distilled out dichloromethane then added 1155 gm methyl cyclohexane, stirred at temperature 50-55 °C to get dissolved followed by cooling to get complete crystallization at temperature 10-15 oC, filtered the mass and washed with methyl cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 580 gm (84%) with HPLC purity 97.58%.

Example 6:
50 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 198 gm dichloromethane is stirred for 5-10 minutes followed by adding 7.82 gm FeCl3 and stirred for 15 minutes then added 60 gm water at temperature 20-30 oC and stirred for 30 minutes followed by adding bromine solution (42.4 gm bromine in 132 gm dichloromethane) at 10-15 oC in 1.5 hours, stirring at temperature 20-25 °C to get complete product formation checked by HPLC, added 75 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 75 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, organic layer washed with 100 gm water, stirred, settle and separate layer at room temperature. Take organic layer and added 100 gm water and adjust the pH 6-7 with caustic lye, stirring and layer separated. Distilled out dichloromethane then crystallization done in 129 gm cyclohexane and stirred at temperature 50-55 °C to get dissolved followed by cooling to complete crystallization at temperature 0-5 oC followed by filtering the mass and washing with cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 53.7 gm (77.8%) with HPLC purity 97.07%.

Example 7:
5 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 20 gm dichloromethane is stirred for 5-10 minutes followed by adding 0.27 gm AlCl3 and stirred for 10 minutes then added 6 gm water at temperature 20-30 oC and stirred for 30 minutes followed by adding bromine solution (4.23 gm bromine in 13.3 gm dichloromethane) at 10-15 oC in 1.5 hours followed by stirring at temperature 20-25 °C to get complete product formation, checked by HPLC. Added 7.5 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 7.5 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, organic layer washed with 10 gm water followed by layer separation at room temperature. Take organic layer and added 10 gm water and adjust the pH 6-7 with caustic lye, stirring and layer separation. Distilled out dichloromethane then added 11.55 gm cyclohexane and stirred at temperature 50-55 °C to get dissolved followed by cooling to complete crystallization at temperature 0-5°C, filtered the mass and washed with methyl cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 5 gm (72.5%) with HPLC purity 96.77%.

Example 8:
5 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 20 gm dichloromethane is stirred for 5-10 minutes followed by adding 0.915 gm TiCl4 and stirred for 10 minutes then added 6 gm water at temperature 20-30 oC and stirred for 30 minutes followed by adding bromine solution (4.23 gm bromine in 13.3 gm dichloromethane) at 10-15 oC in 1.5 hours followed by stirring at temperature 20-25 °C to get complete product formation, checked by HPLC. Added 7.5 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, take organic layer and added 7.5 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, organic layer washed with 10 gm water followed by layer separation at room temperature. Take organic layer and added 10 gm water and adjust the pH 6-7 with caustic lye, stirring and layer separation. Distilled out dichloromethane then added 11.55 gm cyclohexane and stirred to get dissolved at temperature 50-55 °C followed by cooling to complete crystallization at temperature 0-5 oC followed by filtering the mass and washing with methyl cyclohexane to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 4.75 gm (69%) with HPLC purity 95.99%.

Comparative Examples
Example C 1:
100 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 396 gm dichloromethane is stirred for 5-10 minutes followed by adding 15.64 gm FeCl3 and 120 gm water at temperature 20-25 oC, then stirred for 15 minutes and added bromine solution (84.78 gm bromine in 264 gm dichloromethane) at 10-15 oC followed by stirring at temperature 20-25 °C to get complete product formation, checked by HPLC. Added 150 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation. Take organic layer and added 150 gm 10% sodium bisulphite solution, stirred for 30 minutes and performed layer separation, organic layer washed with 200 gm water and performed layer separation. Take organic layer and added 140 gm water and adjust the pH 6-7 with caustic lye, stirring and layer separated. Distilled out dichloromethane and added 145 gm Di-isopropyl ether and heating to 40-45 °C to get completely dissolved it then slowly cool to crystallized at temperature 0-5 oC, filtered the solid and wash with Di-isopropyl ether to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 97 gm (70%) with HPLC purity 95.19%.
Example C 2:
5 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 25 gm acetonitrile is stirred for 5-10 minutes followed by adding 5.58 gm NBS (n-bromo succinimide) and 0.40 gm AIBN (Azobisisobutyronitrile) at temperature 20-30 oC then reaction mass is heated to 60-65 °C to get product formation at temperature 60-65 oC checked by HPLC, reaction complies in 6 hours. Distilled out the solvent acetonitrile followed by adding water and dichloromethane, stirred to get layer separation. Take organic layer distilled out dichloromethane completely and charge 11 gm Di-isopropyl ether and heated to 50-55 °C to get clean solution followed by cooling to 0-5°C, stirred and filtered to get product methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate 4.5 gm (65%) having with HPLC purity 96.16.

Example C 3:
10 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 53 gm dichloromethane is stirred for 5-10 minutes followed by adding 11.16 gm NBS and 0.792 gm AIBN at temperature 20-30 oC then heated to reflux at 40-45 °C to get product formation checked by HPLC, reaction complies in 6 hours but impurity formation is higher , after the reaction complies added water and layer separated, take organic layer and distilled out dichloromethane completely and charge 22 gm Di-isopropyl ether and heated to 50-55 °C to get clean solution followed by cooling to 0-5 °C but materials not getting crystallized because of impurity formation.

Example C 4:
10 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 13.25 gm dichloromethane is stirred then added 9 gm hydrogen peroxide and start the addition of HBr solution (~48%) 5.02 gm in 1-2 hours, stirred and check the reaction progress but reaction not complies even after 10 hours, after that added extra 2.18 gm hydrogen peroxide, stirred and checked the reaction progress, reaction not complies ~20% unreacted compound found.

Example C 5:
5 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 20 gm dichloromethane is stirred followed by adding 15 gm water at temperature 20-30 oC and stirred for 30 minutes followed by adding bromine 3.85 gm at 20-25 oC and stirred to get complete product formation at temperature 20-25 °C, checked the progress of reaction by HPLC, observed the product formation is less and impurity is in higher side ~33.8% by HPLC.

Example C 6
5 gm of Methyl (E)-2-(methoxyimino)-2-(o-tolyl) acetate in 33 gm dichloromethane is stirred followed by adding 6 gm water at temperature 20-30 oC and 0.20 gm AIBN stirred for 10 min followed by adding bromine solution (3.88 gm bromine + 13.25 gm dichloromethane) at 20-25 oC and stirred and checked the reaction by HPLC, Observed more unreacted starting materials, even reaction is not complies after the addition of extra bromine solution (0.99 gm) at temperature 20-25 °C unreacted compound found ~18% by HPLC.

Preparation of (E)-1-(3-(trifluoromethyl) phenyl) ethan-1-one oxime
Example 9:
100 gm of 1-(3-(trifluoromethyl)phenyl) ethan-1-one in 316 gm methanol was stirred at temperature 25 oC for 5-10 minutes and added lot-1 hydroxylamine hydrochloride 33.6 gm and adjust the pH 1-2 with ~47% caustic lye solution and stirred for 60 minute and then added lot-2 of hydroxylamine hydrochloride 9.6 gm followed by pH adjustment to 6-7 with caustic lye solution, stirred for 2-3 hours at 25-30 oC to maximum product formation followed by distillation of methanol under vacuum at temperature at 45-50 oC then added toluene 175 gm and water 200 gm, stirred for 30 minute and layer separated, aqueous layer extracted with 86 gm toluene and combined organic layer distilled out at temperature 60-70 oC under vacuum to get (E)-1-(3-(trifluoromethyl) phenyl) ethan-1-one oxime white crystalline solid 107 gm (99%) with HPLC purity 99.35%.

Comparative Examples
Example C 7:
100 gm of 1-(3-(trifluoromethyl)phenyl)ethan-1-one in 396 gm methanol was stirred at temperature 25 oC for 5-10 minute and added hydroxylamine hydrochloride 36.93 gm and start addition of aqueous NaOH solution (17 gm NaOH in 80 ml water) and stirred for 12 hours reaction not complies, hence added extra 2.5 gm hydroxylamine hydrochloride and stirred further for 2 hours but reaction not complies hence added further hydroxylamine hydrochloride 6.5 gm and stirred further for 2 hours to complies the reaction followed by distillation of methanol under vacuum at temperature at 45-50 oC then charged 150 gm water, stirred and cooled to 0-5oC and filtered it, washed with water to get (E)-1-(3-(trifluoromethyl)phenyl)ethan-1-one oxime 104 gm (97%) with HPLC purity 98.67%.

Example C 8:
10 gm of 1-(3-(trifluoromethyl)phenyl)ethan-1-one in 396 gm methanol was stirred at temperature 25 oC for 5-10 minute and added hydroxylamine hydrochloride 3.7 gm and start addition of aqueous NaOH solution (3.2 gm NaOH in 15 ml water) and stirred for 10 hours at room temperature followed by distillation of methanol under vacuum at temperature 45-50°C then added 45 gm ethyl acetate and 20 gm water added, stirred, layer separated and aqueous layer back extracted in ethyl acetate and combined organic layer distilled at 55-60°C under vacuum to get (E)-1-(3-(trifluoromethyl) phenyl) ethan-1-one oxime 9.8 gm (86%) with HPLC purity 94.67%.

Preparation of Trifloxystrobin
Example 10:
Take 25 gm of (E)-1-(3-(trifluoromethyl)phenyl)ethan-1-one oxime in 78.4 gm acetone at room temperature and charge 42.5 gm of K2CO3 followed by heating at 50-60 °C and stirred for 3 hours, then cool the mass to temperature 25-30 °C and then added solution of intermediate of formula III (38.73 gm methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino)acetate in 39 gm acetone) in 2.5 hours at temperature 25-30 °C, after the addition, added the 1.4 gm TEBAC (Triethyl benzyl ammonium chloride) then heated the reaction mass at 40-45 oC, stirred to get maximum product formation in 8-12 hours followed by salt filtration and distilled out filtrate and crystallization done in 40 gm methanol by heating to 50-55°C to dissolved it followed by cooling to complete crystallization at temperature 0-5 °C, stirred for 60 minute at 0-5 °C, filtered and washed with chilled methanol followed by drying up to constant weight to get Trifloxystrobin 44.98 gm (89.5%) with HPLC purity 99.33%.

Example 11:
Take 45 gm of (E)-1-(3-(trifluoromethyl) phenyl) ethan-1-one oxime in 141 gm acetone at room temperature and charge 76.52 gm of K2CO3 followed by heating to reflux temperature for 3 hours, then cool the mass to temperature 33 °C and then charge 69.7 gm methyl (E)-2-(2-(bromomethyl) phenyl)-2-(methoxyimino) acetate followed by adding 2.5 gm catalyst TEBAC (Triethyl benzyl ammonium chloride). Heated the reaction mass at 40-45 oC, stirred to get maximum product formations followed by salt filtration, distilled out the filtrate mass and crystallization done in 88 gm methanol, heated 50-55°C to dissolve it cooling to complete crystallization at temperature 0-5 °C stirred for 90 minutes at 0-5 °C, filtered and washed with chilled methanol followed by drying up to constant weight to get Trifloxystrobin 80 gm (88.4%) with HPLC purity 99.1%.

Example 12:
Take 51.5 gm of (E)-1-(3-(trifluoromethyl)phenyl)ethan-1-one oxime in 161.5 gm acetone at room temperature and charge 87.42 gm of K2CO3 followed by heating to reflux temperature for 3 hours, then cool the mass to temperature 30 °C and then charged 79.83 gm methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino)acetate followed by adding 2.88 gm catalyst TEBAC (Triethyl benzyl ammonium chloride) then heated the reaction mass at 40-45 oC, stirred to get maximum product formations in 5-10 hours followed by salt filtration and distilled out the filtrate and crystallization in 101 gm methanol, heated at 50-55 °C to dissolve it slowly cooling to complete crystallization at temperature 0-5 °C maintain for 90 minutes and filtered it, washed with chilled methanol followed by drying up to constant weight to get Trifloxystrobin 94.24 gm (91.4%) with HPLC purity 98.78%.

Comparative Examples
Example C 9:
Take 7.45 gm of (E)-1-(3-(trifluoromethyl) phenyl)ethan-1-one oxime in 24 gm acetone, at room temperature added 10 gm methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate and charged 12.07 gm of K2CO3 and 0.56 gm TBAB catalyst followed by maintaining at temperature 25-30 °C under stirring for 5.5 hours, checked the reaction progress, ~92% unreacted compound found, hence heated further to temperature 50-60 °C and again checked the reaction progress but reaction not complies even after the stirring at 50-60 °C for 24 hours.

Example C 10:
Take 20 gm of (E)-1-(3-(trifluoromethyl)phenyl)ethan-1-one oxime in 94 gm acetonitrile at room temperature and charge 40.73 gm K2CO3 followed by maintaining at temperature 30 °C and stirred for 2.5 hours, then added solution of intermediate of formula III (30.97 gm methyl (E)-2-(2-(bromomethyl)phenyl)-2-(methoxyimino) acetate in 63 gm Acetonitrile) in 2-3 hours at temperature 25-30 °C, after the addition, heated the reaction mass at 40-45 oC, stirred to get maximum product formation in 20 hours followed by salt filtration and distilled out filtrate and crystallization in 47 gm methanol by heating at 50-60 oC to dissolved it, followed by cooling to complete crystallization at temperature 0-5 °C, stirred for 60 minutes at 0-5 °C, filtered and washed with chilled methanol followed by drying up to constant weight to get Trifloxystrobin 17 gm (84.5%) with HPLC purity 99.58%.

Thus, from the foregoing description, it will be apparent to one of the person skilled in the art that many changes and modifications can be made thereto without departing from the scope of the invention as set forth in the description. Accordingly, it is not intended that the scope of the foregoing description be limited to the description set forth above, but rather that such description be construed as encompassing such features that reside in the present invention, including all the features and embodiments that would be treated as equivalents thereof by those skilled in the relevant art. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.
,CLAIMS:We Claim:
1. An improved process of preparation of Trifloxystrobin of formula I

Formula I
comprising the steps of:
a) brominating the compound of formula II in presence of Lewis acid catalyst in a suitable solvent

Formula II
to form compound of formula III;

Formula III
b) purifying the obtained compound of formula III using suitable solvent;
c) oximation of the compound of formula IV, using improved process

Formula IV
to form compound of formula V;

Formula V
d) coupling the compound of formula III and compound of formula V, using catalyst in a suitable solvent to form compound of formula I.

2. The process as claimed in claim 1, wherein the brominating agent used in step a) is bromine solution in suitable solvent selected from dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof.

3. The process as claimed in claim 1, wherein the Lewis acid used in step a) is selected from ZnCl2, FeCl3, AlCl3 or TiCl4.

4. The process as claimed in claim 1, wherein the solvent used in step a) is selected from chlorinated solvent such as dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof.

5. The process as claimed in claim 1, wherein purification solvent used in step b) is selected from methyl cyclohexane, cyclohexane or mixtures thereof.

6. The process as claimed in claim 1, wherein in step c) compound of formula IV is undergo oximation reaction using reagent hydroxylamine hydrochloride which is added in two lots to obtain the compound of formula V.

7. The process as claimed in claim 1, wherein in step c) compound of formula V is extracted using a suitable hydrocarbon solvent selected from toluene, xylene or mixtures thereof.

8. The process as claimed in claim 1, wherein in step d) coupling of compound of formula III and formula V is carried out in presence of catalyst Triethyl benzyl ammonium chloride.

9. The process as claimed in claim 1, wherein in step d) coupling of compound of formula III and formula V is carried out in presence of solvents selected from acetone, acetonitrile, propionitrile, methyl ethyl ketone, methyl isobutyl ketone, xylene, toluene or mixtures thereof.

10. An improved process of preparation of compound of formula III

Formula III
by brominating the compound of formula II

Formula II
using bromine solution in suitable solvent selected from dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof in presence of Lewis acid catalyst selected from ZnCl2, FeCl3, AlCl3 or TiCl4 in a suitable solvent selected from chlorinated solvent dichloromethane, ethylene dichloride, monochlorobenzene, chloroform, carbon tetrachloride or mixtures thereof and purifying the obtained compound using suitable solvents selected from methyl cyclohexane, cyclohexane or mixtures thereof.