Patent ID: 8592603

Claim:
A method of preparing a compound of formula 6 comprising: (a) reacting a compound of formula 1 with a compound of formula 2 to form a compound of formula 3 wherein X of formula 2 is Cl or OH; (b) treating the compound of formula 3 with Lawesson's reagent to form a compound of formula 4 (c) reacting a compound of formula 4 with potassium ferricyanide to produce a compound of formula 5 (d) performing catalytic reduction of nitro group of the compound of formula 5 with palladium on charcoal to generate the compound of formula 6, wherein R 1 of formulae 1, 3-6 is C 1-10 haloalkyl, and R 2 of formulae 2-6 is H or C 1-10 alkyl.