A diversity-oriented synthesis of 3-(2-amino-1,6-dihydro-6-oxo-pyrimidin-5- yl)propanoic esters

The synthesis of dimethyl 2-(methoxymethylene) pentanedioates by an unusual Michael addition of 3,3-dimethoxypropionate to α, β-unsaturated esters is described. These new intermediates can subsequently be converted to methyl 3-(2-amino-1,6-dihydro-6-oxo-pyrimidin-5-yl)propanoates upon treatment with guanidine carbonate. The resulting pyrimidine derivatives are open-chain analogues of pyrido[2,3-d]pyrimidines with interesting biological activities.