

THE SYNTHESIS OF 3-NITRO-4H-BENZO[h]CHROMENES

Abstract
A method for the synthesis of 3-nitro-4H-benzo[h]chromenes was developed based on the reaction of 1-naphthoquinone 2-methides generated in situ from Mannich bases with 4-(2-nitrovinyl)morpholine. It was shown that such nucleophiles as morpholine and 4-bromoaniline add to the double bond of the pyran ring.
Keywords
1-naphthoquinone 2-methides; 3-nitro-4H-benzo[h]chromenes; 4-(2-nitrovinyl)morpholine; Mannich bases; push-pull olefins; Diels–Alder reaction; Michael reaction.
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv