CHEMISTRY OF THE 1,3,5-TRIAZA-2-PHOSPHORIN-4,6-DIONES .11. BASE-CATALYZED ADDITION-REACTIONS OF HYL-1,3,5-TRIAZA-2-LAMBDA(4)-PHOSPHORINE-4,6-DIONE TO THE C=N DOUBLE-BOND OF 3-THIAZOLINE HETEROCYCLES

The base-catalyzed reaction of 2-oxo-2-hydro-1,3,5-trimethyl-1,3,5-tri methyl-2 lambda(4)-phosphorine-4,6-dione (1) and of its trimethylsilox y phosphorus(III) derivative (10) with various 3-thiazo-lines (2-5) vi a five different pathways is described. In all cases, the correspondin g 3-thiazoline adducts were formed The different routes ars compared w ith regard to reaction conditions and yields. Tn the reaction of 1 wit h 5,5-dimethyl-2-isopropyl-3-thiazoline (3) two diastereomers of 7 wer e formed, as established by H-1, C-13 and P-31 NMR spectroscopy. The s tructures of the products 6 and 8 were confirmed by X-ray analysis; ti le thiazolidine rings display a twist conformation through the sulfur atom, The molecules are linked via inversion centres by hydrogen bonds of the form N-H ... O=C.