Synthesis
The general procedure for synthesizing 2-chloropyrimidine-5-sulfonyl chloride using 2-hydroxypyrimidine-5-sulfonic acid as a starting material was as follows: referring to the method of Example 26, 2-hydroxypyrimidine-5-sulfonic acid (12.8 g) was mixed with phosphorus pentachloride (37.8 g) and the reaction was stirred for 4 hrs at 180°C. Upon completion of the reaction, the mixture was cooled to room temperature and toluene (200 mL) was added to dissolve the product, followed by filtration to remove insoluble impurities. The filtrate was washed with ice water and dried over anhydrous magnesium sulfate. After removal of the solvent by evaporation under reduced pressure, the residue was allowed to stand in a refrigerator for one day to give 2-chloropyrimidine-5-sulfonyl chloride in the form of a light yellow solid (yield 14.8 g, 96% yield). The product was characterized by 1H-NMR (CDCl3) with chemical shift δ: 9.19 (2H, s).
References
[1] Patent: US2007/60623, 2007, A1. Location in patent: Page/Page column 23
[2] Patent: WO2006/36024, 2006, A1. Location in patent: Page/Page column 159
[3] Patent: EP2336107, 2015, B1. Location in patent: Paragraph 0303
[4] Patent: WO2004/74283, 2004, A1. Location in patent: Page 87
[5] Patent: EP1803709, 2007, A1
