title: Long-acting contraceptive agents: esters of norethisterone with alkoxy- and halogeno-substituted carboxylic acids.
abstract: The chemical synthesis and physical data of several new esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) are reported, which contain either a chloro- or an alkoxy-group as a substituent in the acid side-chain.
mesh_terms: D002264:Carboxylic Acids; D003692:Delayed-Action Preparations; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009640:Norethindrone / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship
chemical_list: D002264:Carboxylic Acids; D003692:Delayed-Action Preparations; D007202:Indicators and Reagents; D009640:Norethindrone