Reductive methylation/phosphorylation of 3,4-diazacyclopentadienone N-oxides with trimethyl phosphite
Treatment of 2,5-diphenyl-3,4-diazacyclopentadienone 3-oxide and 3,4-dioxide with trimethyl phosphite results in N-deoxygenation and methylation and O-phosphorylation to produce dimethyl (1-methyl-3,5-diphenyl-4-pyrazolyl) phosphate.