Abstract The reaction of the di-O-trimethylsilyl derivative of 2-hydroxynicotinic acid with methyl phosphodichloridite afforded 2-methoxy-1, 3, 2-dioxaphosphorino [4, 5-b] pyridin-4 (4 H)-one. The NMR spectrkscopic data suggest that the reaction of the latter with hexafluoroacetone produces unstable 2-methoxy-2, 5-dioxo-4, 4-bis (trifluoromethyl)-4, 5- dihydro-1, 3, 2-dioxaphosphepino [4, 5-b] pyridine, which is readily transformed into 9- ...
