New Pyrrolo(1,2‐c)pyrimidine Derivatives.

The title compounds (IV) (7 examples) are regioselectively obtained in a three-component one-pot reaction between pyridazine (I), phenacyl bromides (II), and 1-butyn-3-one (III) in the presence of 1,2-epoxybutane as reaction medium and acid scavenger.