6
1. 7. 1997.
SELECTIVE SYNTHESIS OF SOME 5-HYDRAZONO-5,6,7,8-TETRAHYDRO-2H-1-BENZOPYRAN-2-ONES
A simple, highly selective transformation of 5,6,7,8-tetrahydro-2H-1-benzopyran-2,5-diones 1–3 and 14 with some phenylhydrazines and heterocyclic hydrazines to 5-hydrazono-2H-1-benzopyran-2-ones 4–12 and 15–16 is described. Under more severe conditions the hydrazonoquinoline derivative 17 was obtained from the benzopyran derivative 3 and Phenylhydrazine.