Imidazole → (1S,2S,4R)-2-({[tert-Butyl(dimethyl)silyl]oxy}methyl)-4-{4-[(1S)-2,3-dihydro-1H-inden-1-ylamino]-7H-pyrrolo[2,3-d]pyrimidin-7-yl)cyclopentyl acetate

Participants

Reaction Steps

(1S,2S,4R)-4-{4-[(1S)-2,3-Dihydro-1H-inden-1-ylamino]-7H-pyrrolo[2,3-d]-pyrimidin-7-yl}-2-(hydroxymethyl)cyclopentanol (3.00 g, 8.23 mmol), 1H-imidazole (1.68 g, 24.7 mmol) and 4-(dimethylamino)-pyridine (100 mg, 0.818 mmol) were dissolved in DMF (90.0 mL) under an atmosphere of argon and the solution was cooled to 0° C. tert-Butyldimethylsilyl chloride (1.24 g, 8.23 mmol) was added and the mixture was stirred at rt for 2 h. LC/MS indicated complete conversion. The reaction was quenched with saturated aqueous sodium chloride solution (30 mL), extracted with EtOAc (3×50 mL), dried with MgSO4, filtered, and concentrated in vacuo. The remaining DMF was removed under high vacuum. Crude (1S,2S,4R)-2-({[tert-butyl(dimethyl)silyl]oxy}methyl)-4-{4-[(1S)-2,3-dihydro-1H-inden-1-ylamino]-7H-pyrrolo[2,3-d]pyrimidin-7-yl}cyclopentanol (3.94 g, 8.23 mmol) and 4-(dimethylamino)-pyridine (100. mg, 0.818 mol) were dissolved in pyridine (70.0 mL) and acetic anhydride (4.66 mL, 49.4 mmol) was added. The mixture was stirred at rt overnight. The solvent was evaporated and the remaining pyridine was removed under high vacuum. The residue was purified via silica gel chromatography eluting with a gradient of 10 to 66% EtOAc in hexanes to afford the title compound (3.66 g, 86%). LC/MS: Rt=2.51 min, ES+ 521 (AA standard).

Provenance & Evidence