Lajos Toldy

Reaction of aminothiazole-oximetosylates with thiols, II

The reaction of ethyl 2-(2-acetyl- or 2-formyl-amidothiazol-4-yl)-2-tosyloxyiminoacetate with thiols in the presence of triethylamine gave the corresponding sulfenylimines. When acetone was used as solvent the reaction led to 2,2-dimethyl-4-(2-acetyl- or 2-formyl-amido-thiazol-4-yl)-5-oxo-2,5-dihydro-1,3-oxazole. In 2-butanone or cyclohexanone similar oxazolinone derivatives were obtained. The structure of the products was elucidated by ir, 1H-and 13C-nmr spectroscopy, and a reaction mechanism is suggested for their formation.

Über die struktur von substituierten isothiuroniumsalzen

Zusammenfassung Bei substituierten Isothiuroniumsalzen der Struktur I kommt i. allg. der Grenzstruktur “a” das grossere Gewicht zu. Dadurch ist das Auftreten von zwei geometrischen Isomeren moglich, deren Umwandlung ineinander mit Hilfe NMR-Messungen quantitativ untersucht wurde. In solchen Losungsmitteln, mit denen ein Protonenaustausch moglich ist, verlauft die E/Z-Isomerisierung nach dem Schema Deprotonierung ⇌ Inversion ⇌ Protonierung, in jenen, wo dies nicht moglich ist, erfolgt eine Rotation um die Cue5fbN-Bindung.

Reaction of aminothiazole-oximetosylates with thiols

The reaction of ethyl 2-(2-acetyl- or 2-formyl-amidothiazol-4-yl)-2-tosyloxyiminoacetate with thiols in the presence of triethylamine gave the corresponding sulfenylimines. When acetone was used as solvent the reaction led to 2,2-dimethyl-4-(2-acetyl- or 2-formyl-amido-thiazol-4-yl)-5-oxo-2,5-dihydro-1,3-oxazole. In 2-butanone or cyclohexanone similar oxazolinone derivatives were obtained. The structure of the products was elucidated by ir, 1H-and 13C-nmr spectroscopy, and a reaction mechanism is suggested for their formation.