Intermediate compound for synthesizing pharmaceutical agent and production method thereof

A method for preparing an optically active 2-{4-(5-substituted-oxadiazolyl) phenyl}morpholine represented by formula 5, which comprises the following steps 1) to 4):

• wherein R1 represents hydrogen atom or a C1-C6 alkyl group, R2 represents a C1-C6 alkyl group, a substituted C 1-C6 alkyl group, or an aryl group,
• 1) reacting a compound represented by formula 1 with an alkali metal salt of hexacyanoferrate(II) or a hydrate thereof at a temperature of from 110° C. to 140° C. in a reaction mixture comprising a Na2CO3, an organophosphorus compound, and a palladium catalyst in a polar aprotic solvent alone or combination of a polar aprotic solvent and other polar aprotic solvent or hydrocarbon solvent to give a compound represented by formula 2,
• 2) reacting the compound represented by formula 2 with hydroxylamine or hydroxylamine hydrochloride at a temperature of from 10° C. to 40° C. in an aprotic polar solvent to give a compound represented by formula 3,
• 3) reacting the compound represented by formula 3 with an acylation reagent selected from the group consisting of aliphatic acyl halides, aromatic acyl halides, aliphatic acyl anhydrides and aromatic acyl anhydrides, and
• 4) keeping the mixture obtained after step 3) at a temperature of from 60° C. to 140° C. to give a compound represented by formula 5.