تحضير مشتقات 2-ايزوكسازولين من أوكزيمات 1،3-ثنائي كربونيل الاريليدين

Novel derivatives of 2-isoxazoline oxime and 5-hydroxy-2-isoxazoline derivatives were synthesized by the oximation reaction of benzylidenacetylacetone and its derivatives with hydroxylamine hydrochloride using two methods. Benzylidenacetyl-acetone was introduced to oximation reaction under strong basic conditions to produce a trans-isomer of 2-isoxazoline oxime with 64% yield. In contrast, the oximation reactions of 2-nitro, 4-methoxybenzylideneacetylacetone derivatives under milder conditions gave various heterocyclic compounds depending on the nature and position of the substituent. The reaction of 2 nitrobenzylidenacetylacetone led to the synthesis of Z and E-isomers of 5-hydroxy-2-isoxazoline derivative with Z/E ratio equal 1:1, and the reaction of 4-methoxybenzylidenacetylacetone gave also Z-and E- 5-hydroxy-2-isoxazoline derivative but the ratio was 1:2 of Z/E isomers.