PURPOSE:To prepare the titled compound useful as a diuretic, in high yield, by adding thioacetic acid to 17-hydroxy-3-oxo-17alpha-pregna-4,6-diene-21-carboxylic acid gamma- lactone in a specific solvent, and separating the addition product by crystallization. CONSTITUTION:17-Hydroxy-3-oxo-17alpha-pregna-4,6-diene-21-carboxylic acid gamma- lactone is made to react with thioacetic acid in N-methyl-2-pyrrolidone or N,N- dimethylacetamide to afford 7alpha-acetylthio-17-hydroxy-3-oxo-17alpha-pregn-4-ene-21- carboxylic acid gamma-lactone, which is then separated by crystallization. EFFECT:The production of by-product is essentially none, and the objective compound can be obtained in high purity. The purification is easy, and the economical effect is significant. The objective compound is prepared in high purity at a stoichiometric yield even by using crude, low-purity raw materials.
展开▼
