FORM 2
THE PATENTS ACT,1970
(39 OF 1970)
COMPLETE SPECIFICATION
(See Section 10; rule 13)
Tiltle: Process for manufacturing Transfluthrin
Applicant: SHOGUN ORGANICS LIMITED, 504, Samartha Vaibhav, Lokhandwala Complex, Off.Link Road, Andheri (W), Mumbai-400 053, Maharashtra, India, An Indian company.
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.


The present invention relates to the process for manufacturing Transfluthrin.
Background and Prior art:
Process synthesis of manufacture of "Transfluthrin" technical. The product is used as active ingredient in mosquito repellant and control products. The process includes the esterification of a tetra fluoro benzyl alcohol with an acid chloride. The product formed has high insect repellant properties. This special synthesis route has been developed for specific use in household insecticide products as an Active ingredient against mosquitoes
The synthesised pyrethroid can be used in specific formulations in India as approved by the Insecticide Registration Committee. This can work as an effective solution to mosquito control. The special 2 step process of synthesis of Transfluthrin technical is highly effective method of manufacture of this high efficacy, low human toxicity product. The chemical sysnthesis route has been invented by us with complete study on it effects on mosquitoes. Effective product is formed which give maximum repellant and knockdown effect to mosquitoes. The synthesis process can be replicated in small Laboratory scale experiments as well as large commercial scale production. It gives consistent results.


Object of Invention:
The process design is used to manufacture a pyrethroid ester insecticide. Its is effective to kill or repel mosquitoes and other insects. Transfluthrin is a fast-acting pyrethroid insecticide with low persistency.Transfluthrin is considered as the best household insecticide active ingredient because of its structure, toxicology and principle of action on the insect nervous system. It should be noted that it is very selective in action and is effective even at extremely low concentrations.
Transfluthrin can be used in the indoor environment against flies, mosquitoes and cockroaches. It is a relatively volatile substance and acts as a contact and inhalation agent The effective process and two step synthesis process would give results. Permethric Acid is reacted with thionyl chloride to form permethric acid chloride (acid chloride) is used for reaction with2,3,5,6 tetrafluoro benzyl alcohol. The ester of this invention can be prepared by the method described.
Staement of the Invention:
Process for manufacturing Transfluthrin comparising the of following steps A & B. A) i) charging 925 grams - 1 R-t-permethric acid to 1.10 Itr solvent tolune in a dry
MS glass reactor at 60°C for 5 hrs followed by refluxing the mass;
ii) adding 720 grams thionyl chloride slowly in the interval of 3.5 hours through
Teflon drip pipe;
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iii) scrubbing of vent gases, namely sulfur dioxide and hydrogen chloride into
multiple scrubbers;
iv) maintaining reflux temperature at 60 to 65 C till the reaction is completed.
v) Vacuum subjecting reactants to vacuum distillation whereby R-t-permethric acid
chloride is formed.
B) i) charving 735 grams 2,3,5,6-tetrafluoro benzylalcohol (TEFA) to 2.540 Itr solvent toluene in a dry MS glass reaction at 60°C for 3 hrs. followed by refluxing the mass; ii) dosing of 1-R-t-permethric acid chloride prepared in Step A to the reaction mass for 4 hours;
iii) scrubbing of vent gas such as hydrogen chloride whereby hydrochloric acid is formed;
iv) the reaction mass is allowed to cool when the reaction is complete; v) washing off with water;
vi) subjecting the solvent for vacuum distillation, removing traces of toluene under high vacuum whereby 95% pure end product is yielded.
Process of Manufacture:
Transfluthnn technical is manufactured in two steps. The chemical reactions and descriptions of each step is given as follows:
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Chemical reactions and their step-wise description
Step l:
Manufacture of 1-R-t- Permethric acid chloride
Chemical reaction:

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To a clean and dry MS glass lined reactor , is charged solvent toluene. 1-R-t-permethic acid is added to the solvent and the reaction mass is heated to reflux.Thionyl chloride is then added very slowly in several hours, through a Teflon drip pipe into the reaction mass. The vent gasses, namely sulfur dioxide and HCL are scrubbed into multiple scrubers. The reaction between 1-R-t-Permethric acid and thionyl chloride is completed . After completion of the reaction ,the solvent is recovered by vaccum distillation. The residual material, 1-R-t-permethric acid chloride(Acid chloride) is used for condensation with 2,3,5,6-tetrafluoro benzyl alcohol (TFBA) as described in the next step. Step 2: Chemical reaction:


Description:
To a clean and dry MS glass lined reactor, is charged solvent toluene. 2,3,5,6-tetrafluoro benzylalcohol (TFBA) is added to the reactor and the reaction mass is heated to reflux temperature. 1 -R-tpermethric acid chloride prepared in step 1 is then dosed into the
reaction mass in several hours. The vent gas HCI is scrubbed into water to obtain a solution of hydrochloric acid. After the completion of the reaction between 2,3,5,6-tetrafluoro benzylalcohol and 1-R-t permethric acid chloride, the reaction mass is cooled, washed with water to remove any free 1-R-t-permethric acid. After washing is completed the solvent is recovered by vaccum distillation and finally the traces of toluene are removed under high vaccum. The product is then analysed for its purity and after it complies with the specifications, it is packed into drums for dispatching. The solvent is recycled to the next batch.
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WE CLAIM:
1. Process for manufacturing Transfluthrin consists of following steps A & B.
A) i) charging 925 grams - 1 R-t-parametric acid to 1.10 ltr solvent toluene in a
dry MS glass reactor at 60oC for 5 hrs followed by refluxing the mass; ii) adding 720 grams thionyl chloride slowly in the interval of 3.5 hours
through Teflon drip pipe; iii) scrubbing of vent gases, namely sulfur dioxide and hydrogen chloride into
multiple scrubbers; iv) maintaining reflux temperature at 60 to 65°C till the reaction is completed; v) Vacuum subjecting reactants to vacuum distillation whereby R-t-permethric
acid chloride is formed;


B)

i) charging 735 grams 2,3,5,6-tetrafluoro benzyl alcohol (TEFA) to 2.540 ltr ■ solvent toluene in a dry MS glass reaction at 60°C for 3 hrs. Followed by
refluxing the,mass; ii) dosing of 1 -R-t-permethric acid chloride prepared in Step A to the reaction
mass for 4 hours; iii) scrubbing of vent gas such as hydrogen chloride whereby hydrochloric acid
is formed; iv) the reaction mass is allowed to cool when the reaction is complete; v) washing off with water; vi) Subjecting the solvent for vacuum distillation, removing traces of toluene
under high vacuum whereby 95% pure end product is yielded.
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2.

The process of manufacturing transfluthnn as described in claim 1 and accompanying chemical reactions


Ath
Dated this 9th day of May, 2007

( AMIT KALYANARAMAN ) JT. MANAGING DIRECTOR For SHOGUN ORGANICS LIMITED