A short and efficient synthetic protocol for the synthesis of 5-substituted-4,6-dioxo-pyrrolo[2,3-d]pyrimidines

A short and efficient synthesis for 5-substituted-4,6-dioxo-pyrrolo[2,3-d]pyrimidines has been developed by the cyclocondensation of α,α-dibromoaldehydes with 2,4-diamino-6-hydroxypyrimidine under mild basic conditions in good yields. Application of this protocol has been demonstrated in the synthesis of a metabolite of Pemetrexed disodium, a novel multi-targeted antifolate.