The general procedure for the synthesis of 4-chloro-6-methylquinazoline from 6-methyl-4-hydroxyquinazoline was as follows: intermediate 10-b (2.1 g, 13.11 mmol) was dissolved in chloroform (30 ml). Oxalyl chloride (1.97 g, 23.26 mmol) and N,N-dimethylformamide (0.1 ml) were subsequently added. The reaction mixture was heated to 100°C and maintained at this temperature for 3 hours. Upon completion of the reaction, the solvent was removed by evaporation to afford intermediate 10 (1.5 g, 58% yield). Mass spectrometry analysis showed m/z = 179 ([M + H]+).
[1] Patent: WO2016/91791, 2016, A1. Location in patent: Page/Page column 20; 21
[2] Patent: WO2016/91774, 2016, A1. Location in patent: Page/Page column 23; 24
[3] Archiv der Pharmazie, 2013, vol. 346, # 1, p. 44 - 52