Patent ID: 7241901
Filing Date: 2007-07-10
Classification: C07C,C07D,Y02P

Abstract:
1. A process for preparing a compound of formula (XI): wherein R 1 represents a hydrogen atom, —CF 3 , or halogen atom; n is an integer from 0 to 5; and R 2 represents a hydrogen atom, a fluorine atom, a chlorine atom, —(C 1 -C 4 )alkyl, —O(C 1 -C 4 )alkyl, —S(C 1 -C 4 )alkyl, or —N(C 1 -C 4 alkyl) 2 group; wherein the process comprises: (a) reacting a compound of formula (V): wherein X 1 represents a halogen atom and R 2 is as defined in the above, with a phenol-group protecting compound in the presence of a base in a solvent at a temperature from −10° C. to 80° C. for a time from 1 hour to 24 hours to form a compound of formula (VI): wherein X 1 and R 2 are as defined in the above, and R 3 represents a phenol-protecting group having a tetrahydropyranyl, —(C 1 -C 4 )alkyl, allyl, or silyl group; (b) subjecting the compound of formula (VI) to halogen-metal substitution and then introducing sulfur thereto to form a compound of formula (VII): wherein R 2 and R 3 are as defined in the above, and M represents a lithium ion or magnesium halide; (c) reacting the compound of formula (VII), without separation, with a compound of formula (IV): wherein R 1 and n are as defined in the above, and X 2 represents a halogen atom or leaving group which can be displaced by nucleophiles, in an anhydrous solvent at a temperature from −100° C. to 25° C. for a time from 0.5 hour to 24 hours, to form a compound of formula (VIII): wherein R 1 , R 2 , R 3 and n are as defined in the above; (d) eliminating the phenol-protecting group of the compound of formula (VIII) in a solvent at from 0 to 120° C. for from 0.5 hour to 24 hours to form a compound of formula (IX): wherein R 1 , R 2 , and n are as defined in the above; (e) reacting the compound of formula (IX) with alkyl halogen acetate in the presence of a base in a solvent at a temperature from −10° C. to 120° C. for a time from 0.5 hour to 24 hours to form a compound of formula (X): wherein R 1 , R 2 , and n are as defined in the above, and R 4 represents a —(C 1 -C 4 )alkyl group; and (f) hydrolyzing a carboxylic ester of the compound of formula (X) in the presence of a water-soluble inorganic base in an alcohol solvent to form the compound of formula (XI).