Synthesis and pharmacological assessment of derivatives of isoxazolo[4,5-d]pyrimidine

A series of new 5-alkyl and 5-arylisoxazolo4,5-d]pyrimidinones (5a-g, 6-8) were prepared from 4-amino-3-oxo-isoxazolidine-5-carboxylic acid amide. Some of the aryl derivatives of isoxazolo4,5-d]pyrimidine were tested pharmacologically in comparison with Diazepam. Compounds 5b-d and 7 demonstrated interesting anxiolytic activity.