反应详情

This step is a step for obtaining compound (2-5) by reducing the triple bond of compound (2-4) to a double bond. Compound (2-5) can be obtained by using a catalyst such as Lindlar's catalyst, palladium-barium sulfate or the like in a solvent such as tetrahydrofuran, ethyl acetate, acetonitrile, methanol, ethanol or the like and under a hydrogen atmosphere. A preferable solvent is ethyl acetate. In order to obtain a favorable result, 0.1 to 1 equivalent of quinoline may be added with respect to compound (2-4). A catalytic amount to an excess of catalyst is used with respect to compound (2-4). The reaction temperature is room temperature, the reaction time is from 15 minutes to 24 hours, and the reaction pressure is from 1 to 4 atmospheres.