Isothiazoles. Part X. New 3-substituted-2-arylpropenamidines by base catalyzed ring opening of 3-amino-4-arylisothiazole 1,1-dioxides.

Starting from 5-unsubstituted or 5-alkyl-, aryl-, heteroarylsubstituted 3-d iethylamino-4-arylisothiazole 1,1-dioxides by base induced ring opening 3-a lkoxypropenamidines were synthesized in excellent yields in a mild and effi cient way. When 5-bromo-3-diethylamino-4-arylisothiazole 1,1-dioxide was us ed as the reagent, 3,3-dialkoxy-propenamidines, a new class of unsaturated amidines, were obtained. By using Grignard reagents 3-substituted acrylamid ines can be produced. (C) 1999 Elsevier Science Ltd. All rights reserved.