Patent ID: 7923557
Filing Date: 2011-04-12
Classification: A61P,C07D

Abstract:
1. A method for regioselectively preparing a compound represented by formula (I): or a salt thereof, wherein: X is —NH—; G is —O—, —O—C(O)—NH—, —O—C(O)—NR R R R R R n is 1 or 2; m is 0 or 1; Y is O, S, or NR R the method comprising the steps of: a) reacting HNR  wherein R b) adding a strong base to the first mixture in at least 2 separate portions, and the mixture is maintained at a temperature of between about −20° C. and about 10° C., comprising the regioisomers represented by formulas (IIIa) and (IIIb) and a compound represented by formula (II): thereby forming a second mixture of regioisomers represented by formulas (IVa), (IVb), and (IVc): c) adding a hydrocarbon solvent to the second mixture after the reaction is substantially complete and stirring the mixture for between about 1 hour to about 2 hours; d) heating a suspension comprising hydrazine, and the regioisomers represented by formulas (IVa), (IVb), and (IVc) in a polar solvent, thereby forming a third mixture comprising regioisomers represented by formulas (VIa), (VIb) and (VIc): e) adding water to the third mixture of regioisomers represented by formulas (VIa), (VIb), and (VIc), wherein the volume of water added is about 1 to about 4 times the volume of the polar solvent; f) allowing the compound represented by formula (VIa) to selectively precipitate out of the mixture at room temperature; g) collecting the precipitate comprising a compound represented by formula (VIa); h) heating in the presence of a catalytic amount of an acid the precipitate comprising a compound represented by formula (VIa) and a compound represented by the formula R