<i>p</i>-Methoxy- and 2,4-Dimethoxybenzyl <i>N</i>-Acetylcarbamate Potassium Salts: Versatile Reagents for <i>N</i>-Alkylacetamide and <i>p</i>-Methoxy- and 2,4-Dimethoxybenzyl Carbamates

Abstract

The acetamide moiety is a general functional group present in many natural and pharmaceutical products. Herein, we report two new reagents, p-methoxybenzyl N-acetylcarbamate potassium salt (PM-BENAC-K) and 2,4-dimethoxybenzyl N-acetylcarbamate potassium salt (2,4-DM-BENAC-K), which are refined versions of the benzyl N-acetylcarbamate potassium salt (BENAC-K). These compounds, which we reported as simple equivalents of N-acetamide nucleophiles, are stable and easy-to-handle powders that react with a variety of alkyl halides and sulfonates to afford substituted products in good yields. The products were transformed into N-alkylacetamides after p-methoxybenzyloxycarbonyl (Moz) or 2,4-dimethoxybenzyloxycarbonyl (Dmoz) cleavage under mild acidic conditions. The acetyl groups in the substituted products of PM-and 2,4-DM-BENAC-Ks were removed using K 2 CO 3 in methanol to afford Moz-and Dmoz-protected amines, respectively. Hence, the new BENAC-Ks acted as versatile equivalents of both N-acetamide and Moz/Dmozprotected nitrogen nucleophiles and can be used in synthetic studies of natural and pharmaceutical products.