Synthesis
A mixture of 5-ethynylpyrimidine-4,6-diamine (300?mg, 2.24?mmol), Cs2CO3 (1.46?g, 4.47?mmol) and DMSO (4.00?ml) in a 10.00?ml microwave tube was irradiated at 100?W and 180?°C for 15?minutes. After this time, the reaction mixture was cooled to room temperature and poured into a separating funnel containing 100?ml water and 100?ml ethyl acetate. The aqueous layer was extracted with EtOAc (2×100?ml). The combined organic extracts were dried with MgSO4 and filtered through celite, and excess solvent was removed in vacuo. Purification by column chromatography (80?% EtOAc/hexane – 10?% MeOH/CH2Cl2) gave 7H-pyrrolo[2,3-d]pyrimidin-4-amine (4-Amino-7H-pyrrolo[2,3-d]pyrimidine) (0.15?g, 50?%) as an off-white solid[1].