4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidine

5661-01-8

83942-13-6

General procedure for the synthesis of 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-one from 1,5,6,7-tetrahydrocyclopenta[d]pyrimidin-4-one: 11 mL of phosphorochloride was added to 6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-ol (1.56 g, 11.4 mmol) made in step C. The mixture was stirred under reflux conditions for 4 hours. After completion of the reaction, the reaction solution was cooled to room temperature. Subsequently, dichloromethane (DCM) was added to the reaction solution and diluted with water. The aqueous layer was extracted with DCM, and after combining the organic layers, it was purified by column chromatography to finally obtain 4-chloro-6,7-dihydro-5H-cyclopentapyrimidine (1.67 g, 95% yield). The product was characterized by 1H-NMR (DMSO-d6): δ 8.78 (1H, s), 3.03 (2H, t), 2.99 (2H, t), 2.10 (2H, m).