Synthetic routes to 1,5-dihydro-5-oxo-4,1-benzoxazepines and to 5-oxooxazolo[3,2-a]quinolines
作者:Sham S. Gandhi、Karen L. Bell、Martin S. Gibson
DOI:10.1016/0040-4020(95)00880-h
日期:1995.11
The literature concerning phenacyl anthranilate, N- phenacylanthranilic acid and phenacyl N-phenacylanthranilate is clarified. Phenacyl anthranilate is dehydrated to 1,5-dihydro-5-oxo-2-pheny 1-4,1-benzoxazepine by treatment with phosphoryl chloride; other examples of this reaction are described. A preparation of 4-methyl-5-oxo-2-phenyloxazolo[3,2-a]quinoline from N-phenacylanthranilic acid and propionic
Applicability of the previously described rearrangement of 2-oxo-2-phenylethyl 2-amino-benzoate leading to 2-phenyl-2-hydroxymethyl-2,3-dihydroquinazolin-4(1H)-one has been studied. To test the limits of the reaction, various starting compounds such as 2-oxopropyl 2-aminobenzoate, 2-oxo-2-phenylethyl 2-aminobenzoate and 3,3-dimethyl-2-oxobutyl 2-aminobenzoate as well as some of their corresponding N-methyl and N-phenyl analogues were used. The structure-reactivity dependence was observed giving the expected products only in specific cases and in limited yields. Structure of the dihydroquinazolin-4(1H)-one skeleton was unambiguously confirmed with use of X-ray analysis of two selected compounds. Finally, an alternative way for the preparation of the desired derivatives was developed.