Patent ID: 6506902
Filing Date: 2003-01-14
Classification: C07D

Abstract:
A method of synthesizing a compound of formula I, comprising:(a) reacting a compound of formula II wherein R1 and R2 are independently hydrogen, hydroxy(C1-C2)alkyl, or (C1-C2)alkyl with, a compound of formula III wherein R3, R4, and R5 are each independently of each other hydrogen, (C1-C3)alkyl, (C1-C3)alkoxy, or halogen; and X is a leaving group, in a solvent having a dielectric constant at 20Â° C. of at least 30 but no more than 40, and wherein the solvent and amount of solvent dissolve compounds II and III, but precipitate at least a portion of the compound of formula I during the reacting step; and (b) obtaining the compound of formula I.