反应详情

In a 3 L 3 neck flask with a mechanical stirrer, DMAP (11.5 g, 0.10 mmol) was added to a solution of 3-amino-thiophene-2-carboxylic acid methyl ester (105 g, 0.95 mmol) and in pyridine (750 mL). A solution of (BOC)2O (222 g, 1.02 mol) in pyridine (750 mL) was slowly added to the previous solution while the temperature was kept between 20 and 25° C. The mixture was stirred under nitrogen for 20 h. The reaction mixture was evaporated to dryness then triturated in 500 mL of MeOH at rt for 3 h then 30 min at 0° C. The suspension was filtered on a buchner funnel and washed with cold ethanol. The white solid was dried to afford 175 g (70%) of 3-tert-Butoxycarbonylamino-thiophene-2-carboxylic acid methyl ester.

1. customwas kept between 20 and 25° C
2. customThe reaction mixture was evaporated to dryness
3. customthen triturated in 500 mL of MeOH at rt for 3 h
4. custom30 min
5. customat 0° C
6. filtrationThe suspension was filtered on a buchner funnel
7. washwashed with cold ethanol
8. customThe white solid was dried