Dimethyl Sulfoxide → Pyrimidine

Participants

Reaction Steps

Reacting XIX with an excess of guanidine carbonate in an organic solvent, preferably a polar aprotic solvent such as dimethylsulfoxide (DMSO), dimethylformamide (DMF), or N,N-dimethylacetamide, at a temperature of 80° to 200°, preferably 100° to 160°, ambient pressure and preferably under an inert atmosphere, yields both XXI and XX as products. The products are isolated upon dilution of the reaction mixture with, for example, acetone and water successively. Higher reaction temperatures and longer reaction times (e.g., in DMSO at 130°-150° for 2 to 8 hours) favor the production of the furopyrimidine XXI over the uncyclized pyrimidine XX.

Provenance & Evidence