Regioselective hydrodehalogenation of 3,5-dihaloisothiazole-4-carbonitriles: synthesis of 3-haloisothiazole-4-carbonitriles
摘要:
3,5-Dibromoisothiazole-4-carbonitrile 1 treated with Zn or In dust (5 equiv) and HCO2H undergoes regioselective hydrodebromination to give 3-bromoisothiazole-4-carbonitrile 3 in 70-74% yield. Similarly, 5-bromo and iodo 3-chloroisothiazole-4-carbonitriles 8 and 9 give 3-chloroisothiazole-4-carbonitrile 4 in 77 and 85% yields, respectively. Also hydrodeamination of 5-amino-3-chloroisothiazole-4-carbonitrile 7 using isoamyl nitrite gives the latter in 95% yield. The dibromoisothiazole 1 reacts with Zn dust in either DCO2D or HCO2D to give 3-bromo-5-deuterioisothiazole-4-carbonitrile 10 in 71 and 58% yields, respectively. The 3-bromoisothiazole 3 reacts with cyclic dialkylamines to give the corresponding 2-(dialkylaminomethylene)-malononitriles and not the expected 3-dialkylaminoisothiazole-4-carbonitriles. Finally, the 3-bromoisothiazole 3 is readily converted into both 3-bromoisothiazole-4-carboxamide 19 and the carboxylic acid 20. All products are fully characterized. (C) 2011 Elsevier Ltd. All rights reserved.
Several 1,1'-dicyano-2-substituted ethylenes (2-16) were synthesized and evaluated for in vivo antifilarial activity. Some of the screened compounds showed significant antifilarial response against Acanthocheilonema viteae in rodents. (C) 1997 Elsevier Science Ltd.
Regioselective hydrodehalogenation of 3,5-dihaloisothiazole-4-carbonitriles: synthesis of 3-haloisothiazole-4-carbonitriles
作者:Heraklidia A. Ioannidou、Panayiotis A. Koutentis
DOI:10.1016/j.tet.2011.03.065
日期:2011.5
3,5-Dibromoisothiazole-4-carbonitrile 1 treated with Zn or In dust (5 equiv) and HCO2H undergoes regioselective hydrodebromination to give 3-bromoisothiazole-4-carbonitrile 3 in 70-74% yield. Similarly, 5-bromo and iodo 3-chloroisothiazole-4-carbonitriles 8 and 9 give 3-chloroisothiazole-4-carbonitrile 4 in 77 and 85% yields, respectively. Also hydrodeamination of 5-amino-3-chloroisothiazole-4-carbonitrile 7 using isoamyl nitrite gives the latter in 95% yield. The dibromoisothiazole 1 reacts with Zn dust in either DCO2D or HCO2D to give 3-bromo-5-deuterioisothiazole-4-carbonitrile 10 in 71 and 58% yields, respectively. The 3-bromoisothiazole 3 reacts with cyclic dialkylamines to give the corresponding 2-(dialkylaminomethylene)-malononitriles and not the expected 3-dialkylaminoisothiazole-4-carbonitriles. Finally, the 3-bromoisothiazole 3 is readily converted into both 3-bromoisothiazole-4-carboxamide 19 and the carboxylic acid 20. All products are fully characterized. (C) 2011 Elsevier Ltd. All rights reserved.
Hydrogenation of Imino‐bisnitriles—Synthesis of Novel Triamines