New access to pyrazole, oxa(thia)diazole and oxadiazine derivatives

✍ Scribed by Alaa A. Hassan; Kamal M. El-Shaieb; Raafat M. Shaker; Dietrich Döpp

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 126 KB
• Volume: 16
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.20071

✦ Synopsis

Abstract

1,4‐Disubstituted thiosemicarbazides 1b–f reacted with ethenetetracarbonitrile (5) in di‐ methylformamide with formation of 2‐substituted 5‐phenyl‐1,3,4‐thiadiazoles 2a–f and 2‐substituted 5‐phenyl‐1,3,4‐oxadiazoles 4a–f. Upon addition of 5 to 1c–e in chlorobenzene, 3‐amino‐2‐benzoyl‐4,5,5‐tri‐ cyano‐2,5‐dihydro‐1__H__‐pyrazole‐1‐[N‐(4‐tricyanovi‐nyl)phenyl]carbothioamide (12), 5‐benzylamino‐, and 5‐allylamino‐4‐benzoyl‐2,3‐dihydro‐[1,3,4]thiadiazol‐ 2,2‐dicarbonitrile (13a,b) and 5‐amino‐1‐benzoylpyrazole‐3,4‐dicarbonitrile (14) as well as 2‐phenyl‐ 4__H__‐[1,3,4]‐oxadiazine‐5,6‐dicarbonitrile (15) were formed. Rationales for the role of the solvent and the conversions observed are presented. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:12–19, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20071