Synthesis and reactivity of 2-(benzothiazol-2-yl)-1-bromo-1,2-ethanedione-1-arylhydrazones

✍ Scribed by Ahmad M. Farag; Kamal M. Dawood

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 184 KB
• Volume: 8
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/(sici)1098-1071(1997)8:1<45::aid-hc6>3.0.co;2-1

✦ Synopsis

The novel, highly versatile 2-(benzothiazol-2-yl)-1bromo-1,2-ethanedione-1-arylhydrazones 3 were prepared and their behavior toward some nucleophiles was investigated. Thus, reaction of 3 with the sodium salt of malononitrile afforded the aminopyrazolecarbonitriles 5 that undergo cyclocondensation with hydrazine, formic acid, and formamide to give the corresponding pyrazolo [3,4-d]pyridazine 6, pyrazolo [3,4-d]pyrimidinone 7, and pyrazolo [3,4d]pyrimidine 8 derivatives, respectively. Similarly, reactions of 3 with each of acetylacetone, dibenzoylmethane, and benzoylacetonitrile afforded the corresponding pyrazole derivatives 9, 10, and 11, respectively. The latter products undergo cyclocondensation with hydrazine to afford the corresponding pyrazolo [3,4-d]pyridazines 12, 13, and 14, respectively.