Pyridine → 6-(2,2-Diphenyl-ethylamino)-9-((1R,4S)-4-ethoxycarbonyloxy-cyclopent-2-enyl)-9H-purine-2-carboxylic acid methyl ester

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Reaction Steps

6-(2,2-Diphenyl-ethylamino)-9-((1R,4S)-4-hydroxy-cyclopent-2-enyl)-9H-purine-2-carboxylic acid methyl ester (2.80 g, 6.14 mmol) is placed in an oven-dried flask under an atmosphere of argon. Dry tetrahydrofuran (30 ml) is added followed by dry pyridine (0.97 g, 12.3 mmol). Ethyl chloroformate (2.66 g, 24.6 mmol) is added slowly and the reaction mixture is stirred at room temperature. The reaction is shown to be complete by LCMS after 3 hours. The solvent is removed in vacuo and the residue is partitioned between dichloromethane (200 ml) and 1M HCl (2×200 ml). The organic layer is washed with saturated sodium bicarbonate solution (2×200 ml), water (2×100 ml), brine (2×100 ml), dried over MgSO4, filtered and the solvent is removed in vacuo. The title compound is obtained after purification by flash column chromatography (silica, 4% MeOH in dichloromethane). MS (ES+) m/e 528.3 (MH+).

Provenance & Evidence