作者:Do Young Ra、Nam Sook Cho、Jae Joo Cho
DOI:10.1002/jhet.5570350306
日期:1998.5
4-thiadiazolin-2-one (2) was undertaken selectively at either the 3-NH position or at 5-amino group depending on reaction conditions. The 3-NH is highly acidic and acylation takes place with acid anhydrides at this position in high yields in the presence of pyridine or triethylamine. The diacylation of both the 3-position and the 5-amino group was only possible via the 5-amino-3-acyl-1,3,4-thiadiazolin-2-one
根据反应条件,在3-NH位置或5-氨基选择性地进行5-氨基-3 H -1,3,4-噻二唑啉-2-酮(2)的酰化。3-NH是高酸性的,在吡啶或三乙胺的存在下,在该位置用酸酐以高收率进行酰化反应。只有通过5-氨基-3-酰基-1,3,4-噻二唑啉-2-酮中间体4才能使3-位和5-氨基的二酰基化。在中性条件下,酰化仅在5-氨基上与酰基氯形成5-酰基氨基-3 H -1,3,4-噻二唑啉-2-酮5发生。5-乙酰氨基-3 H-1,3,4-噻二唑啉-2-酮还可以通过在乙酸中热转化5-氨基-3-乙酰基-1,3,4-噻二唑啉-2-酮来合成。