CYCLIZATION OF NITRILES. XXIII. ADDITION OF ACTIVE PHENOLS TO ELECTRON-DEFICIENT ETHYLENES, ACCOMPANIED BY CYCLIZAION TO 2-AMINO-4H-BENZOPYRANS. CRYSTAL STRUCTURE OF 2-AMINO-4-(2-FLUOROPHENYL)-3-ETHOXYCARBONYL-4H-NAPHTHOPYRAN
Active phenols and also 2-naphthol react with arylidene derivatives of malononitrile and cyanoacetic ester with the formation of the corresponding substituted 2-amino-4H-benzo- and 2-amino-4H-naphthopyrans.By X-ray crystallographic investigation