| 摘要 |
<p>Novel compounds of the following general formulae <FORM:1046044/C2/1> <FORM:1046044/C2/2> wherein R is an alkyl group (C1-C5), R1 is hydrogen or carboxylic acyl, R11 is a hydrogen or halogen atom or an alkyl or alkoxy (C1-C5) are prepared by reacting a thiazolium compound of formula <FORM:1046044/C2/3> or the corresponding thiol of the formula <FORM:1046044/C2/4> (particularly in the form of its S-sodium salts) with a benzoyl phosphonic acid diester of formula <FORM:1046044/C2/5> wherein R, R1 and R11 are as defined above and X is an alkyl group (C1-C5), an aryl group, or an aralkyl group having not more than 15 carbon atoms. The reaction results in the formation of a mixture of the compounds of the first two formulae above. The presence of less than about 0.5 mol of water per mol of reactant is inclined to favour the formation of the pyrimidopyrimidinethiazine compound of the first general formula above. The pyrimido-pyrimidothiazine can be converted into the thiazine compound by hydrolysis</p> |
