Expeditious routes to 4-alkoxyquinazoline-2-carbonitriles and thiocarbamates via N-arylimino-1,2,3-dithiazoles using microwave irradiation

✍ Scribed by Thierry Besson; Marie-Joëlle Dozias; Jérôme Guillard; Patrick Jacquault; Marie-Dominique Legoy; Charles W. Rees

• Book ID: 104208575
• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 603 KB
• Volume: 54
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(98)00276-2

✦ Synopsis

Conversion of N-arylimino-4-chloro-5H-l,2,3-dithiazole 11 into the 4-alkoxyquinazoline-2carbonitriles 13a-i and of the aryl isothiocyanates 15 into aryl thiocarbamates 16a-j with sodium alkoxides in the corresponding alcohol, either by conventional thermolysis or by microwave irradiation are described and directly compared. Microwave irradiation of the solutions in open vessels in a monomode system with focused irradiation and continuous temperature control (Synthewave $402 reactor) usually gave cleaner, faster and higher yielding reactions. These reactions could be safely and beneficially scaled up to muhigram quantities in a larger reactor (Synthewave S 1000).