Sulfuric Acid → (5,6-Dimethyl-3-oxo-2-benzofuran-1(3H)-ylidene)acetonitrile

Participants

Reaction Conditions

Reaction Steps

2-Azido-6,7-dimethyl naphtho-1,4-quinone (2.0 g) was added in small portions (10 mg) to cold (0°-5° C.), vigorously stirred concentrated sulphuric acid (30 ml. over 11/2 hours and the red solution stirred a further 10 minutes at 3° C. until nitrogen evolution ceased. Poured onto ice-water (400 g) whereby the phthalide separated as a whitish solid. After recrystallisation from ethanol in the presence of charcoal the white solid had m.p. 165°-181° C. (mixture of E and Z isomers). (Found; C, 72.10; H, 4.77; N, 6.91; C12H9NO2 requires; C, 72.35; H, 4.55; N, 7.03%).

Provenance & Evidence