4-Methyl-5-ethyl-2-thiouracil reacts with ethyl bromide in alcoholic solution in presence of sodium ethylate, forming 2-ethylmercapto-4-methyl-5-ethyl-uracil (m. p. 141°),from which 2-ethylmercapto-4-methyl-5-ethyl-6-chloropyrimidine, boiling at 148-150° at 13 mm., at 164-166° at 17 mm., or at 180-185° at 25 mm., is prepared according to the directions given by Johnson and Bailey. This chloro-pyrimidine reacts with sodium methylate in methyl alcohol forming 2-ethyl-mercapto-4-methyl-5-ethyl-6-methoxypyrimidine, boiling at 152-154° at 11 mm., at 156-160° at 16.5 mm., or at 162° at 22 mm., and with sodium ethylate in ethyl alcohol forming 2-ethylmercapto-4-methyl-5-ethyl-6-ethoxypyrimidide, boiling at 139-140° at 5 mm,or 142-145° at 7 mm.