C–H Phosphonation of Pyrrolopyrimidines: Synthesis of Substituted 7- and 9‑Deazapurine-8-phosphonate Derivatives

The Mn­(OAc)3-promoted C–H phosphonation of 7-deazapurines (pyrrolo­[2,3-d]­pyrimidines) and 9-deazapurines (pyrrolo­[3,2-d]­pyrimidines) with diethylphosphite was developed. The reactions occur regioselectively at position 8 both in 7 and 9-deazapurines, leading to new deazapurine-8-phosphonate derivatives, which can be further modified and transformed to 6-(het)­aryl-deazapurine derivatives or deprotected to free phosphonic acids.