Studies on the reactions of substituted 4-0X0 -2-thi O- and 2, 4-DIOXO- 3, 4-DIHYDRO- 2H-1, 3-benzoxazines

Abstract EN

Reactions of substituted and unsubstituted salicyloyl chlorides with methylthiocyanate lead to the formation of thiobenzoxa/ines.

These compounds subsequently react with ammonia, and hydrazine hydrate to form thiourea, and thiosemicarbazide derivatives, respectively.

These reactions take place through opening of the oxazine ring.

On the other hand, reactions with amino acid esters give substituted 2-N-methyI or ehtyl acetato-4-oxo- [3, 4, -d] -benzoxazines.

These reactions arc achieved by the retention of oxazine ring in the product.

Consequently the side chain of these last products can be cyclized to give a new series of tricyclic imidazobenzoxines.