Synthesis
The general procedure for the synthesis of dimethyl pyrimidine-4,6-dicarboxylate from methanol and pyrimidine-4,6-dicarboxylic acid was as follows: 10 g (0.059 mol) of pyrimidine-4,6-dicarboxylic acid was suspended in 1.4 L of methanol, followed by the addition of 10.93 mL (0.356 mol) of concentrated hydrochloric acid. The reaction mixture was stirred at reflux for 3 hours at 65 °C. Upon completion of the reaction, the reaction mixture was concentrated under reduced pressure and the residue was redissolved in methanol. After filtration of the mixture, the filtrate was concentrated to afford the product dimethyl pyrimidine-4,6-dicarboxylate in a yield of 11.02 g (94.4% yield). Mass spectrometry (ES+) analysis showed m/e = 197.20.
References
[1] Patent: US2003/229103, 2003, A1. Location in patent: Page 9
[2] Journal of Medicinal Chemistry, 2008, vol. 51, # 22, p. 7053 - 7056
[3] Patent: WO2010/43866, 2010, A2. Location in patent: Page/Page column 77
[4] Journal of Medicinal Chemistry, 2017, vol. 60, # 1, p. 307 - 321