X= H, 3-01 4-NO,; Z= 0, NH, NCH,, NCB, the final step. N-Hydroxymethylphthalimide24 was allowed to react with acetylacetone in concentrated H2S04 in a known manner2'to give the diacetylethylphthalimide 40 (X= H). Similarly, N-hydroxymethyl-3-and 4-nitrophthalimidez were converted to 40 (X= 3-or 4-No2). Treatment of these materials with H2NOH HC1 in acetic acid at reflux27 gave excellent yields (> go%) of isoxazoles 41 (Z= 0), thus ...