| 摘要 |
<p>Compounds having one of the following probable formula <FORM:1002886/C2/1> wherein R1 represents hydrogen, alkyl, cycloalkyl, aryl optionally substituted (e.g. by Cl, Br, alkyl or alkoxy), aralkyl optionally substituted (e.g. by Cl, Br, alkyl or alkoxy), or a heterocyclic radical (e.g. pyridine, thiazole, thiophene or pyrazole) optionally substituted (e.g. by Cl, Br, alkyl or alkoxy), and R2 represents hydrogen or aryl optionally substituted (e.g. by Cl, Br, alkyl or alkoxy), are prepared by reacting one mole of formaldehyde with two moles of a 5-bromo-2-amino-thiazole of the formula <FORM:1002886/C2/2> in acetic acid solution and in the presence of a mineral acid. The 5-bromo-2-amino-thiazoles used as starting materials are prepared by brominating 2-amino-thiazoles in presence of sodium acetate, glacial acetic acid and chloroform. Specifications 808,629 and 853,587 are also referred to.</p> |
