1208082-91-0

The reaction was carried out with 3,5-dibromopyrazin-2-amine (5 g, 19.8 mmol) and 2-chloroacetone (18.3 g, 198 mmol) in dioxane (40 ml) at reflux temperature for 16 hours. After completion of the reaction, the mixture was concentrated under reduced pressure and the resulting residue was ground with diisopropyl ether (DIPE) to give intermediate 101 (3.6 g, 55% yield).

[1] Patent: WO2010/89292, 2010, A1. Location in patent: Page/Page column 93
[2] Patent: US2012/83492, 2012, A1. Location in patent: Page/Page column 92
[3] Patent: US9993554, 2018, B2. Location in patent: Page/Page column 243