SYNTHESIS OF PHOSPHORUS-CONTAINING HETERO CYCLES FROM 2-AMINONICOTINIC ACID

The reaction of 2-aminonicotinic acid with ethyl chloroformate, follow ed by alkylation with NaH/MeI and decarboxylation with methylamine, le d to N-methyl-2-(methylamino)nicotinamide (3). Treatment of 3 with PCl 3 in the presence of triethylamine gave the phosphorinanone 4. Substit ution of chlorine in 4 by the dimethylamino-, N,N,N'-trimethylethylene diamino-, or bis(2-chloroethyl)amino group furnished 5-7. Hydrolysis o f 4 with small amounts of water formed the phosphoryl derivative 8 as the hydrochloride. The spirophosphoranes 9 and 10 were produced by rea ction of 5 with hexafluoroacetone and tetrachloro-o-benzoquinone, resp ectively. In order to evaluate its coordination ability, the N,N,N'-tr imethylethylenediamino-substituted diazaphosphorinanone 6 was allowed to react with the tetracarbonyl norbornadiene derivatives of chromium( 0) and molybdenum(0). The cis-substituted tetracarbonyl complexes 12 a nd 13 were formed. In the reaction of 7 with dichloro(1,5-cyclooctadie ne)platinum(II) the cis-disubstituted complex 15 was formed. A compari son of benzo- and pyrido-annulated phosphorinanones was made, and thei r differences were discussed. In the case of the compounds 2, 7, and 9 single-crystal X-ray structure analyes were performed. In 9 the heter ocycle C and N atoms are coplanar (the phosphorus Lies 60 pm outside t he plane); P and N(2) are displaced in 7 to the same side of the plane of the remaining four atoms.