反应详情

Thiophene (42 g, 0.5 mol), paraldehyde (4.4 g, 0.033 mole) and 4-isopropylbenzamide (16.3 g, 0.1 mol) were added to a mixture of formic acid (40 ml) and 85% phosphoric acid (20 ml) and stirred at a room temperature for three hours. The reaction mixture was extracted with water (70 ml). An organic phase was washed with water (30 ml) and evaporated to dryness with a rotary evaporator. A residue was recrystallized from carbon tetrachloride/petroleum benzine (1:2) to obtain the entitled compound (20.7 g) as a colorless crystal. Yield: 75.8%. Melting point: 100° C.

1. extractionThe reaction mixture was extracted with water (70 ml)
2. washAn organic phase was washed with water (30 ml)
3. customevaporated to dryness with a rotary evaporator
4. customA residue was recrystallized from carbon tetrachloride/petroleum benzine (1:2)