Synthesis of bis-(2-chloroethyl)amino-substituted diazaphosphorinones. Reversible oxidative addition of hexafluoroacetone to sigma(3)lambda(3)-phosphorus compounds. Synthesis of sigma(5)lambda(5)-spirophosphoranes and their decomposition

The reaction of 1-methyl-pyrido[3,2-e]-3,1-oxazin-2,4-dione (1) with benzyl amines led to the aminonicotinic acid amides 2-4. Their reaction with phosp horus trichloride furnished the P-chloro-pyridodiazaphosphorinones 5-7, whi ch, upon reaction with bis-(2-chloroethyl) ammonium chloride/triethylamine, were converted into the P-bis-(2-chloroethyl) amino-substituted pyridodiaz aphosphorinones 8-10. The P-chloro-benzodiazaphosphorinone 11 was allowed t o react with 2-chloroethylammonium chloride/triethylamine to form the 2-chl oroethylamino-substituted derivative 12. The sigma(3)-diazaphosphorinones 8 , 9, 12 and 13 were oxidized with the urea-hydrogen peroxide-(1:1)-adduct t o the corresponding phosphoryl derivatives 14-17. The oxidative addition of hexafluoroacetone (HFA) to the sigma(3)-diazaphosphorinone 18 led, with ab straction of methyl chloride. to the tricyclic phosphorane 19 b. The spirop hosphoranes 21-23 were formed by reaction of compounds 8, 9 and 13 with HFA . NMR-studies were made on the decomposition of the bicyclic phosphoranes 2 0a, 22 and 23. The oxidative addition of HFA to diazaphosphorinones was fou nd to be reversible. Single crystal X-ray determinations were conducted on compounds 17 and 19b. They confirm the expected connectivity. Compound 17 w as found to exhibit short C-H .. O-hydrogen bonds (H...O 234 pm). Compound 19 crystallises as two independent molecules which differ, e.g., in the ori entation of the chloroethyl groups.