Novel base-induced reactions of substituted (1,2-benzisoxazol-3-yl)acetates

Abstract

The reactions of substituted (1,2-benzisoxazol-3-yl) acetates with strong bases are described. The esters (1) and (2) having electron-donating and dialkylamino substituents undergo novel ring transformations on treatment with NaH, Bu^tOK, or MeONa in DMF to afford the 2H-azirines (8) and the 3-iminobenzofurans (18), respectively, while under similar conditions the halogeno esters (3) dimerize to give the ethylenedicarboxylate (24). Treatment of the esters (4)–(7) having electron-withdrawing substituents with NaH in DMF results in the recovery of the starting esters. However, on treatment of the sulphinyl esters (6) with MeONa in methanol, C-S bond cleavage occurs to afford methyl arylsulphinates (27).