Reactions of 2-acyloxyisobutyryl halides with nucleosides. 6. Synthesis and biological evaluation of some 3'-acyl derivatives of 2,2'-anhydro-1-(.beta.-D-arabinofuranosyl)cytosine hydrochloride

Abstract

The reactions of cytidine with 22 2-O-acyloxyisobutyryl chlorides lead to the isolation of the corresponding 2,2''-anhydro-1-(3''-O-acyl-.beta.-D-arabinofuranosyl)cytosine [3''-O-Ac cycloC] hydrocholorides 9. These compounds, which show cytotoxicity against HeLa [human cervical cancer] cells in tissue culture, were examined for antiviral and antileukemic activity. Activity against DNA viruses (vaccinia and herpes) in tissue culture is maximal in compounds containing acyl groups with 8-12 carbon atoms. Activity against L1210 leukemia in mice varies markedly according to the length of the acyl groups, and high activities were observed for long-chain (C16-C22) esters. The reaction between cytidine and O-acetylsalicyloyl chloride provides an alternate route for the synthesis of 3''-O-Ac cycloC hydrochloride.