反应详情

4.5 g (13 mmol) of ethyl 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-oxo-1,2-dihydroquinoxaline-3-carboxylate was dissolved in ethanol (100 ml), and 4.1 g (26 mmol) of a 25% aqueous solution of sodium hydroxide was added thereto. The solution was stirred for 2 hours at room temperature. The reaction mixture was concentrated under reduced pressure and water was added to the residue thus obtained. The mixture was acidified using 10% hydrochloric acid. A solid precipitated therefrom was separated by filtration, washed with water, and then dried to obtain 3.9 g (yield: 94%) of 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-oxo-1,2-dihydroquinoxaline-3-carboxylic acid as a pale yellow powder.

1. concentrationThe reaction mixture was concentrated under reduced pressure and water
2. additionwas added to the residue
3. customthus obtained
4. customA solid precipitated
5. customtherefrom was separated by filtration
6. washwashed with water
7. customdried