Long-acting contraceptive agents: norethisterone esters of arylcarboxylic acids

The synthesis of esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxy-estr-4-en-3-one) with acids containing a benzene ring is described, two methods of esterification being compared in terms of yield and convenience. The activities of these esters as long-acting contraceptive agents have been evaluated.