An improved synthesis of 2-nitrobenzo(b)furans
Résumé
2-Nitrobenzo(b)furans 4 are prepared in improved yields by reacting o-hydroxybenzaldehydes 1 and bromonitromethane (2) at low temperature in order to avoid the dehydration of the aldol intermediate 3 in the alkaline condensation medium. This aldol 3 is then quantitatively dehydrated by heating in acetic anhydride.