反应详情

A suspension of 4.6 g (20 mmol) of 2-(4-aminophenyl)-4-hydroxy-5-pyrimidine carboxylic acid, 2.36 ml (30 mmol) of ethyl isocyanate, and 70 ml of dimethylformamide is stirred at room temperature and 2.8 ml (20 mmol) of triethylamine is added. The resulting solution is allowed to stand overnight at room temperature and another 2.36 ml (20 mmol) of ethyl isocyanate is added. After 6 hrs the dimethylformamide is evaporated under high vacuum and the residue is treated with 100 ml of water. The solid is filtered and dried to give 1.5 g of 2-[4-(N-ethylcarbamoylamino)phenyl]-4-hydroxy-5-pyrimidine carboxylic acid. The filtrate is acidified to pH 2.5 with hydrochloric acid and another 3.10 g of acid is obtained.

1. customAfter 6 hrs the dimethylformamide is evaporated under high vacuum
2. additionthe residue is treated with 100 ml of water
3. filtrationThe solid is filtered
4. customdried