Synthesis of β-Keto Esters In-Flow and Rapid Access to Substituted Pyrimidines

We have developed an in-flow process for the synthesis of β-keto esters via the BF3·OEt2-catalyzed formal C−H insertion of ethyl diazoacetate into aldehydes. The β-keto esters were then condensed with a range of amidines to give a variety of 2,6-substituted pyrimidin-4-ols.