7672-94-8Relevant articles and documents
Generalized method for the production of 1,3-benzoxazine, 1,3-benzothiazine, and quinazoline derivatives from 2-(hydroxy, thio, or amino) aromatic acids using triphenylphosphine thiocyanogen
Pritchard, Kaylene M.,Al-Rawi, Jasim M.,Hughes, Andrew B.
, p. 1601 - 1611 (2007/10/03)
A modified one-pot method was developed for the synthesis of 1,3-benzoxazines, in which the preparation of unstable thiocyanogen was omitted. The method was found to be general for substituted (methyl, methoxy, halo, and hydroxy) 2-hydroxy benzoic acids and 2-hydroxy naphthoic acids. The method was extended to 2-thio, 2-amino, and N-methyl aminobenzoic acid with which the synthesis of 1,3-benzothiazine and quinazoline derivatives has been achieved, respectively. It was also found that 3-hydroxypyridine-2-carboxylic acid and 2-hydroxynicotinic acid using a modified method gave 2-thioxo-2,3-dihydro-4H- pyrido[2,3-e][1,3]oxazin-4-one and 2-thioxo-2,3-dihydro-4H-pyrido[3,2-e][1,3] oxazin-4-one, respectively. The structures of the new compounds were confirmed by the analysis of their IR, 1H, and 13C NMR spectra. Copyright Taylor & Francis, Inc.
