A convenient synthesis of 4, 6-dihydro-2-methyl-pyrimidine can be obtained by cyclization reaction of acetamidine hydrochloride and diethyl malonate in the presence of sodium methoxide for a 91.2 % yield. 4, 6-Dihydro-2-methyl-5-nitropyrimidine can be achieved by nitration under the mixed acids of nitric acid, trichloroacetic acid and acetic acid in an 88.3 % yield and then the chlorination using phosphorus oxytrichloride can afford 4,6-Dichloro-2-methyl-5-nitropyrimidine with an 82.6 % yield.
[1] Asian Journal of Chemistry, 2014, vol. 26, # 12, p. 3559 - 3561
[2] Patent: US6849647, 2005, B1. Location in patent: Page/Page column 134
[3] Journal of Medicinal Chemistry, 2000, vol. 43, # 22, p. 4288 - 4312
[4] Patent: US6107300, 2000, A
[5] Patent: US6245769, 2001, B1
