Efficient and selective deprotection method for N-protected 2(3H)-benzoxazolones and 2(3H)-benzothiazolones
作者:Pascal Carato、Saïd Yous、Didier Sellier、Jacques H. Poupaert、Nicolas Lebegue、Pascal Berthelot
DOI:10.1016/j.tet.2004.08.070
日期:2004.11
moieties are frequently used in medicinal chemistry. The synthesis of derivatives bearing a free NH often requires the use of a protection method. A literature search reveals very few protection/deprotection methods for cyclic carbamates. In this paper, we described different methods applicable to 2(3H)-benzoxazolone and 2(3H)-benzothiazolone.
Acylation and Alkoxycarbony-lation of Benzoxazoline-2-thione and Benzothiazoline-2-thione
作者:Takehiko Nishio、Kiyoko Shiwa
DOI:10.3987/com-03-s(p)10
日期:——
Acylation of benzoxazoline-2-thione (1) and benzothiazoline-2-thione (2) with acetic anhydride (3) and acyl chlorides (4) gave N-acyl (5, 6) and/or S-acyl (7, 8) derivatives depending on the nature of acylating agents and bases used. Alkoxycarbonylation of 1 with aralkyl chlorocarbonates (9) gave N-alkoxycarbonyl derivatives (10) mainly, while that of 2 with aralkyl chloroccarbonates (9) gave S-alkoxycarbonyl derivatives (12) exclusively. Photolysis of N-acyl derivatives (5 or 6) in the presence of alcohols afforded 1 or 2, respectively, together with esters (16).