Haloacetylated enol ethers. 9. Synthesis of 4‐trifluoromethyl‐2‐methyl[phenyl]pyrimidines and tetrahydro derivatives

The synthesis of 4‐trifluoromethyl‐2‐methyl[phenyl]pyrimidines and the corresponding tetrahydro derivatives from the cyclo‐condensation reaction of β‐alkoxyvinyl trifluoromethyl ketones 1a‐d with acetamidine or benzamidine hydrochloride, is reported. For the cyclo‐condensation of 1a‐d with acetamidine and benzamidine hydrochloride, two methods were tested: 1 M solution of sodium hydroxide (method A) and sodium alkoxide/alcohol (method B). Depending on the structure of the β‐alkoxyvinyl trifluoromethyl ketones and the reactions conditions, pyrimidines or tetrahydropyrimidines or a mixture of both compounds were obtained.