反应详情

To a solution of ethyl 1H-imidazole-2-carboxylate (701 mg, 5 mmol) in DMF (20 ml) was dropwise added potassium tert-butoxide (5.50 ml, 5.50 mmol). The reaction turned cloudy in the middle of the addition. The mixture was stirred for 30 minutes before O-(4-nitrobenzoyl)hydroxylamine (911 mg, 5.00 mmol) in DMF (10 mL) was added dropwise. The reaction turned dark blue and then brown and finally orange as the addition continued. The reaction was stirred at room temperature overnight and poured into aqueous NaHCO3 (150 mL) to form a clear yellow solution which was extracted with CH2Cl2 (4×200 ml). The organic layers were combined and evaporated in vacuo to provide ethyl 1-amino-1H-imidazole-2-carboxylate (760 mg, 98% yield) as a yellow solid.

1. additionin the middle of the addition
2. additionwas added dropwise
3. additionbrown and finally orange as the addition
4. customto form a clear yellow solution which
5. extractionwas extracted with CH2Cl2 (4×200 ml)
6. customevaporated in vacuo