ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Photoisomerization of Some 2-Alkylthiobenzothiazoles

A. Gáplovský, R. Hercek, and P. Kuráň

Institute of Chemistry, Comenius University, SK-842 15 Bratislava

E-mail: gaplovsky@fns.uniba.sk

Abstract: Photolysis of 2-benzylthio-, 2-diphenylmethylthio-, 2-allylthio-, 2-(methoxycarbonylmethylthio)-, 2-(1-naphthylmethylthio)-, and 2-(2-naphthylmethylthio)benzothiazole (Ia-If) was studied. Photoreactivity of these compounds was dependent on the type of the alkyl moiety as well as on the energy of applied radiation. The main products of photolysis of studied benzothiazoles were the corresponding 3-alkyl-3H-benzothiazole-2-thiones (IIa-IIf) and 3H-benzothiazole-2-thione (III). The ratio between these two groups of formed thioketones IIa-IIf and III was dependent on the character of the substituent in position 2 of the benzothiazole skeleton. Benzothiazole (IV) and products formed by dimerization of radicals derived from substituent were the other products of photolysis. The predominant formation of the corresponding IIa and IIb was observed with Ia and Ib only. For all studied thioethers except of Ic an irreversible photoisomerization was observed. An increase of yield of III on account of IIa-IIf was found after sensitized photolysis of thioethers Ia-If (λ_irr > 290 nm).

Full paper in Portable Document Format: 551a45.pdf

Chemical Papers 55 (1) 45–48 (2001)