反应详情

A mixture of methyl 3-amino-5-(4-chlorophenyl)-2-thiophenecarboxylate (37.3 mmol, 10.0 g) and N,N-dimethylformamide dimethyl acetal (74.7 mmol, 8.9 g) in ethanol (350 mL) was heated at reflux for 3 hours. The solvent was removed by rotary evaporation. To the residue 15 mL of toluene was added and the solvent was removed by rotary evaporation. This was repeated three times. To the resulting sticky residue, 20 mL hexanes was added followed by the gradual addition of ethyl acetate at 0° C. until it solidified. The resulting solid was collected by filtration giving the product (11.9 g, 98.9%). 1H NMR (CDCl3): δ 3.08 (6H, d, J=6.5 Hz), 3.81 (3H, s),6.98 (1 H. s), 7.35 (2H, d, J=8.6 Hz), 7.53 (2H, d, J=8.5 Hz), 7.69 (1H, s). LCMS m/z=323 (m+H+).

1. temperaturewas heated
2. temperatureat reflux for 3 hours
3. customThe solvent was removed by rotary evaporation
4. additionTo the residue 15 mL of toluene was added
5. customthe solvent was removed by rotary evaporation
6. additionTo the resulting sticky residue, 20 mL hexanes was added
7. additionfollowed by the gradual addition of ethyl acetate at 0° C. until it
8. filtrationThe resulting solid was collected by filtration