LITHIATION AND DETHIACARBONYLATION OF A HETEROCYCLIC THIOAMIDE CYCLO-C6H4O.C(=S)NH BY REACTION WITH SOLID LI2S IN THE PRESENCE OF HEXAMETHYLPHOSPHORAMIDE - SYNTHESIS AND CRYSTAL-STRUCTURE OF CYCLO-[C6H4O.C(=S)NLI.HMPA]2.C6H4(OH)NH2

Solid Li2S reacts with a solution of C6H4O.C(=S)NH and hexamethylphosphoramide (HMPA) in toluene to give [C6H4O.C(=S)NLi.mu2-HMPA]2.C6H4(OH)NH2, 1, in which two equivalents of the organic acid have been lithiated while a third equivalent has been stripped of its C=S group and di-protonated; structurally, complex 1, which can also be prepared directly by reacting Bu(n)Li, C6H4O.C(=S)NH, HMPA and NH2C6H4OH in 2:2:2:1 amounts, is unique in having a heterobifunctional ligand (NH2C6H4OH) bridging two Li+ centres in the same molecule.