A serious of C4‐position aniline functionalized 5H‐pyrano[2,3‐d]pyrimidine derivatives were synthesized from the corresponding chlorinated pyrimidines and acetanilides. This process was approached by treating the acetanilide with NaH instead of aniline, where a dissociation of the acyl group in situ happened during the reaction. The strategy worked out the non‐reactive route resulted from the low reactivity of aniline. This C−N bond formation features mild reaction conditions, simple execution, and broad substrate scope.