反应详情

Cyclisation of the 3-(p-cyanophenoxy)-3-methybut-1-yne (9.77 g) was accomplished by heating in diethylaniline at 210°-220° C. under nitrogen. Purification by distillation, and extraction with dilute hydrochloric acid gave 2,2-dimethyl-6-cyano-2H-benzo[b]pyran as a colourless oil (6.84 g), which slowly crystallised on standing, having a nmr spectrum showing signals at δ 1.46, 6.25 (d, J=10), 5.67 (d, J=10,), 6.74 (d, J=8), 7.18 (d, J=2), 7.34 (q, J32 8, 2).

1. customPurification
2. distillationby distillation, and extraction with dilute hydrochloric acid