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[摘要]：Alkylation of (3,4-dihydro-4-oxo-2H-1,3-benzothiazin-2-ylidene)acetate and -acetonitrile with phenacyl chlorides in the presence of K2CO3 occurs at the N atom yielding the corresponding N-phenacyl derivs. The latter, upon treatment with DMF.POCl3, were converted into 1-aroyl-9-oxo-9H-pyrrolo[2,1-b][1,3]benzothiazine-3-carboxylates and -3-carbonitriles, resp. The structure of the obtained pyrrolobenzothiazines was confirmed unambiguously by x-ray crystallog. on 1-benzoyl-9-oxo-9H-pyrrolo[2,1-b][1,3]benzothiazine-3-carboxylate [monoclinic, space group P21/c, a 21.977(1), b 10.833(1), c 15.888(1) ? b 110.08(1)? V 3552.8(3) ?, Z 8]. Reaction of these pyrrolo[2,1-b][1,3]benzothiazines with aliph. primary amines resulted in the thiazine ring cleavage and formation of 2-[(5-aroyl-3-cyano(or ethoxycarbonyl)-1H-pyrrol-2-yl)thio]-N-alkylbenzamides. |
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