Synthesis
Preparation of 2-chloroadenine: 2,6-dichloropurine (0.877 kg, 4.64 mol) was placed in a 20 L autoclave and a methanol solution of ammonia (7.0 N, 6.95 kg) was added. After sealing the autoclave, stirring was initiated and the mixture was heated to 100 °C. The reaction was maintained at this temperature for 17 hours. After completion of the reaction, the mixture was cooled to room temperature. After complete cooling, the autoclave was opened and the reaction mixture was diluted with deionized water (3.5 kg). The resulting solid suspension was collected by filtration and the filter cake was washed with methanol (2 x 0.7 kg). Subsequently, the product was dried to constant weight in a vacuum oven at 40 °C to afford 2-chloroadenine as a light yellow solid (0.725 kg, 4.28 mol, 92% yield).
References
[1] Bioorganic and Medicinal Chemistry, 2003, vol. 11, # 24, p. 5501 - 5508
[2] Heterocycles, 2013, vol. 87, # 11, p. 2369 - 2384
[3] Nucleosides, Nucleotides and Nucleic Acids, 2005, vol. 24, # 5-7, p. 1127 - 1130
[4] Patent: WO2005/70947, 2005, A1. Location in patent: Page/Page column 12-13
[5] Patent: WO2018/19681, 2018, A1. Location in patent: Page/Page column 46; 47