Control of the reaction between 2-aminobenzothiazoles and Mannich bases. Synthesis of pyrido[2,1-b][1,3]benzothiazoles versus [1,3]benzothiazolo[2,3-b]quinazolines
Control of the reaction between 2-aminobenzothiazoles and Mannich bases. Synthesis of pyrido[2,1-b][1,3]benzothiazoles versus [1,3]benzothiazolo[2,3-b]quinazolines
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2-氨基苯并噻唑与曼尼希碱之间反应的控制。
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
J. N. Low
中科院分区：
文献类型：
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作者：
J. Quiroga;P. Hernández;B. Insuasty;R. Abonía;J. Cobo;Adolfo Sánchez;M. Nogueras;J. N. Low
2-氨基苯并噻唑与曼尼希碱的反应选择性地受位阻控制。吡啶[2,1-b][1,3]苯并噻唑3是用非位阻曼尼希碱如3-（二甲氨基）丙烯酮盐类2生产的，而[1,3]苯并噻唑[2,3-b]喹唑啉是用大的曼尼希碱如2-（二甲氨基甲基）四酮4生产的。与2-氨基-5-（乙基磺胺基）噻二唑的反应表明了这一点，之前报道的与2的反应遵循前一种反应途径，而与4的反应遵循后一种反应途径。通过核磁共振和x射线衍射确定了最终结构，从而确定了环化过程。
Reactions between 2-aminobenzothiazoles and Mannich bases are observed to be selectively controlled by the steric hindrance in the latter. Pyrido[2,1-b][1,3]benzothiazoles 3 are produced with non-sterically hindered Mannich bases such as 3-(dimethylamino)propiophenone hydrochlorides 2, whilst [1,3]benzothiazolo[2,3-b]quinazolines are produced with bulky Mannich bases such as 2-(dimethylaminomethyl)tetralone 4. This is shown by reactions with 2-amino-5-(ethylsulfanyl)thiadiazole, which was previously reported to follow the former reaction pathway with 2, while the reaction with 4 follows the latter reaction pathway. The final structures are established by NMR and X-ray diffraction, thus confirming the cyclization processes.