反应详情

2.8 g of 3,7-dihydroxy-phthalide (see Examples 105 and 106) are introduced into a solution of 7.5 g of potassium cyanide in 35 ml of water, and 25 ml of concentrated hydrochloric acid are slowly added to the mixture while cooling with ice, so that the internal temperature does not exceed 10° C. The reaction mixture is maintained at room temperature for a further 5 hours and then the crystals are filtered off. Having been washed with water and dried well, the product (m.p. 213°-215° C.) is pure 4-hydroxy-1,3-dihydro-3-oxo-1-isobenzofurancarboxamide.

1. additionare slowly added to the mixture
2. temperaturewhile cooling with ice, so that the internal temperature
3. customdoes not exceed 10° C
4. filtrationthe crystals are filtered off
5. washHaving been washed with water
6. customdried well