反应详情

A suspension of 267.3 mg of 4-(2-amino-4-thiazolyl)-2-methoxy-6-nitrophenol in 10 ml of dry methylene chloride is treated at -20° with 1.25 g of boron tribromide. After the addition the mixture is stirred at -20° for a further 1 hour and at room temperature without cooling for 18 hours. The reaction mixture is then evaporated, the residue is treated cautiously with water and stirred at 50° for 30 minutes. After cooling to room temperature the mixture is suction filtered and the crude product is removed by filtration and washed with a small amount of water. There is obtained 5-(2-amino-4-thiazolyl)-3-nitropyrocatechol hydrobromide of m.p. 244°-246° (from methanol).

1. additionAfter the addition the mixture
2. temperaturewithout cooling for 18 hours
3. customThe reaction mixture is then evaporated
4. additionthe residue is treated cautiously with water
5. stirringstirred at 50° for 30 minutes
6. temperatureAfter cooling to room temperature the mixture
7. filtrationfiltered
8. customthe crude product is removed by filtration
9. washwashed with a small amount of water