| 摘要 |
PURPOSE:To produce a thiophene useful as an intermediate for synthesis of medicines and agrochemicals with high selectivity by reacting a 1,4-dialdehyde derivative with hydrogen sulfide in the presence of hydrogen chloride. CONSTITUTION:A thiophene of formula II is produced by reacting a compound of formula I (R is H, an alkyl or an aryl; A is a protected formyl) with hydrogen sulfide in the presence of hydrogen chloride in a solvent (e.g. methanol) or without using a solvent at 70 to 180 deg.C. Hydrogen sulfide and hydrogen chloride are used in an amount of 0.75 to 2mol and 0.001 to 0.5mol respectively based on 1mol compound of formula I. In this production method, coexistence of a catalytic amount of hydrogen chloride enables advantageous production of thiophene or a thiophene derivative having a substituent group at 3 position under a mild condition. |
