Patent ID: 6844350

Claim:
A febrifugine represented by Formula (A): synthesized by a method which comprises subjecting an S-aldehyde compound represented by Formula (C): (wherein R 1 represents a silyl group and R 2 represents a cyclic hydrocarbon group) to a Mannich reaction with a 2-alkoxyaniline compound and a 2-alkoxypropene compound in the presence of an aqueous Lewis acid of a rare earth metal, in an aqueous solvent, to form a diastereomeric mixture of a β-aminoketone compound represented by Formula (D): (wherein R 1 and R 2 are as defined above, and R 3 represents an alkyl group which forms an alkoxy group of the 2-alkoxyaniline), after which the anti-diastereomer is cyclized to form a piperidine compound, and reacted with a quinazoline compound to obtain a febrifugine represented by the Formula (A).