Synthesis of 2-(3-acylselenoureido)benzonitriles and 2-(3-acylselenoureido)thiophene- 3-carbonitriles 5a-5f by addition of 2-aminonitriles 4a-4c to benzoyl- or 2,2-dimethyl- propanoylisoselenocyanate and their cycloaddition reactions are described. Structures of compounds 5a-5f were supported by CIMS, FTIR, 1H, 13C, 77Se and 15N NMR spectra. The parameters of 15N and 77Se nuclei were obtained from inverse 1H-X 2D HMBC and GSQMBC correlation experiments at natural abundance. Structure of compound 5b was confirmed by X-ray analysis. The geometry of 5b was optimized by ab initio RHF/DZVP quantum chemistry calculation. A very good correlation between the calculation and experimental data was found. The geometry of 5e was optimized by ab initio DFT/VWN/DZVP quantum chemistry calculation. It was found that title compounds 5a-5f do not undergo isomerization to acylisoselenoureas, in contrast to analogous ester derivatives. Fused 6-imino-6H-1,3- selenazinium salts (chlorides 6a-6f, hydrogensulfates 7a-7f and tetrafluoroborates 8a-8f) were prepared by an acid cyclization of 5a-5f. It was found that neutralization of 6a-6f, 7a-7f and 8a-8f led to their retrocyclization to 5a-5f. Selenoureas 5a-5f with equimolar amounts of methanolic potassium hydroxide afforded potassium salts 9a-9f. Only the salts 9b, 9c, 9e and 9f of the thiophene series were isolated. Their heating in methanol solution led to deacylation of isoselenoureas 10b and 10c. The in situ prepared compounds 9a and 9d cyclized and deacylated to 4-aminoquinazoline-2-selenole 11a under the same conditions. The compounds 5a-5f and 10a-10c cyclized to fused 4-aminopyrimidine-2-selenols 11a, 11b and 4-aminopyrimidine-2-selenone 12c by boiling in methanolic potassium hydroxide solution.
描述了通过将2-氨基腈4a-4c加入苯甲酰或2,2-二甲基丙酰异硒氰酸酯中合成2-(3-酰基硒脲基)苯甲腈和2-(3-酰基硒脲基)噻吩-3-碳腈5a-5f及其环加成反应。化合物5a-5f的结构由CIMS、FTIR、1H、13C、77Se和15N NMR光谱支持。在自然丰度下,通过逆1H-X 2D HMBC和GSQMBC相关实验获得了15N和77Se核的参数。化合物5b的结构通过X射线分析得到确认。化合物5b的几何构型通过ab initio RHF/DZVP量子化学计算进行优化。发现计算和实验数据之间有很好的相关性。化合物5e的几何构型通过ab initio DFT/VWN/DZVP量子化学计算进行优化。发现与类似的酯衍生物不同,标题化合物5a-5f不会发生酰基异硒脲的异构化。通过酸环化反应制备了融合的6-亚氨基-6H-1,3-硒杂环盐(氯化物6a-6f、硫酸氢盐7a-7f和四氟硼酸盐8a-8f)。发现中和6a-6f、7a-7f和8a-8f会导致它们的逆环化为5a-5f。硒脲5a-5f与甲醇钾氢氧化物等摩尔量的甲醇钾氢氧化物生成了钾盐9a-9f。只分离出噻吩系列的盐9b、9c、9e和9f。它们在甲醇溶液中加热后会脱酰基成为异硒脲10b和10c。在相同条件下,原位制备的化合物9a和9d在环化和脱酰基的情况下形成了4-氨基喹唑啉-2-硒烯11a。化合物5a-5f和10a-10c在甲醇钾氢氧化物溶液中煮沸后会环化为融合的4-氨基嘧啶-2-硒醇11a、11b和4-氨基嘧啶-2-硒酮12c。