Synthesis and michael reaction of 3,4-dimethylpyrrole

A two step synthesis of 3,4-dimethylpyrrole via the reduction of 3-carboethoxy-4-methyl-pyrrole is described. Michael addition of methyl vinyl ketone and butyn-2-one to 3,4-dimethylpyrrole gives the bisadducts, 2,5-bis(3-oxobutyl)-3,4-dimethylpyrrole and 2,5-bis(3-oxobutenyl)-3,4-dimethylpyrrole, respectively, while ethyl propiolate affords only the monoadduct, ethyl 3-(3,4-dimethylpyrrol-2-yl)propenoate. Catalytic reduction of the latter ester gives ethyl 3-(3,4-dimethylpyrrol-2-yl)propanoate which with ethyl propiolate gives ethyl 3-(5-carbethoxyethyl-3,4-dimethyl-2-yl)propenoate.