Synthesis
GENERAL STEPS: An aqueous solution (3 mL) of sodium hydroxide (2.85 g, 71.3 mmol) was slowly added to an aqueous solution (50 mL) of diethyl oxalacetate sodium salt (8.7 g, 50 mmol) under stirring conditions with continuous stirring for 20 minutes. Subsequently, cyclopropanecarboxamidine hydrochloride (5.0 g, 40 mmol) was added to the reaction system and the mixture was heated to 70 °C and kept reacting overnight. Upon completion of the reaction, the mixture was cooled to room temperature and the pH was adjusted to 1 by careful dropwise addition of concentrated hydrochloric acid.The precipitated solid was separated by filtration and dried to afford 2-cyclopropyl-6-hydroxypyrimidine-4-carboxylic acid (4.7 g, 63% yield). The product was characterized as follows: 1H NMR (400 MHz, d6-DMSO) δH 13.3 (1H, br s), 12.97 (1H, br s), 6.59 (1H, s), 1.94 (1H, quintuple peak), 1.04 (4H, m) ppm.
References
[1] Patent: WO2009/81112, 2009, A2. Location in patent: Page/Page column 114
[2] Patent: WO2010/92339, 2010, A1. Location in patent: Page/Page column 83-84
