Synthesis of bisfurazanobenzo-2,1,3-thiadiazole and related compounds.
作者:TOSHIO UNO、KANAME TAKAGI、MUNEMITSU TOMOEDA
DOI:10.1248/cpb.28.1909
日期:——
Nitration of 4, 7-dibromobenzo-2, 1, 3-thiadiazole (I) with fuming nitric acid afforded 4, 7-dibromo-5, 6-dinitrobenzo-2, 1, 3-thiadiazole (II) and, unexpectedly, the tribromo derivative : C6Br3N3O2S (III). Compound II was readily converted by treatment with sodium azide into bisfuroxanobenzo-2, 1, 3-thiadiazole (IV), which was reduced with triethylphosphite to give bisfurazanobenzo-2, 1, 3-thiadiazole (VII). Compound VII was also synthesized starting from 4-bromo-6, 7-(2', 1', 3'-oxadiazole) benzo-2, 1, 3-thiadiazole (VIII). Reduction of VII with sodium hydrosulfite gave 4, 5-diamino-6, 7-(2', 1', 3'-oxadiazole)-benzo-2, 1, 3-thiadiazole (XI), which was cyclized to 4, 5-(2', 1', 3'-oxadiazole) benzo [1, 2-c : 3, 4-c'] bis [1, 2, 5] thiadiazole (XII) by treatment with N-sulfinylaniline. The transformation of XII to benzo [1, 2-c : 3, 4-c' : 5, 6-c"] tris [1, 2, 5] thiadiazole (XIV), via 4, 5-diaminobenzo-[1, 2-c : 3, 4-c'] bis [1, 2, 5] thiadiazole (XIII), is also described.
用发烟硝酸硝化 4,7-二溴苯并-2,1,3-噻二唑(I),得到 4,7-二溴-5,6-二硝基苯并-2,1,3-噻二唑(II),并意外地得到三溴衍生物:C6Br3N3O2S(III)。化合物 II 经叠氮化钠处理后很容易转化为双呋喃并苯并-2,1,3-噻二唑(IV),再经亚磷酸三乙酯还原,得到双呋喃并苯并-2,1,3-噻二唑(VII)。化合物 VII 也是从 4-溴-6,7-(2',1',3'-恶二唑)苯并-2,1,3-噻二唑(VIII)开始合成的。用亚硫酸氢钠还原 VII 得到 4,5-二氨基-6,7-(2',1',3'-恶二唑)-苯并-2,1,3-噻二唑(XI),再用 N-亚磺酰苯胺处理,环化成 4,5-(2',1',3'-恶二唑)苯并 [1,2-c : 3,4-c'] 双 [1,2,5] 噻二唑(XII)。还描述了 XII 通过 4,5-二氨基苯并[1,2-c : 3,4-c' ]双[1,2,5]噻二唑(XIII)转化为苯并[1,2-c : 3,4-c' ]三[1,2,5]噻二唑(XIV)的过程。