Synthesis, spectroscopic studies and insecticidal properties of isoxazolyltin(IV) compounds

Heteroleptic tetraorganotins have been synthesised by reacting triorganotin chlorides with 3,5-dimethylisoxazole lithiated a priori at the C-4 ring at om or at the exocyclic C-7 position. Triorganostannyl esters of 3-methyliso xazole-5-yl acetic acid and 3,5-dimethyl isoxatole-4-carboxylic acid were a lso synthesised by condensing triorganotin hydroxides or bis(triorganotin) oxides with these acids. Both classes of organotin products were characteri sed by elemental analyses, IR, multinuclear (H-1, C-13 & Sn-119) NMR and Sn -119m Mossbauer spectroscopy; X-ray crystal structure analysis of 3-methyl- 5-[tris(p-chlorophenyl) stannylmethyl] isoxazole confirmed the spectroscopi c assignment of a tetrahedral geometry at tin for the molecule. Four carbox ylates showed uncommonly high inhibitory potency when screened in-vitro aga inst the enzyme acetylcholinesterase.