Methyl iodide → 7-chloro-2-[(R)-3-methoxypyrrolidine-1-carbonyl]thieno[3,2-b]pyridine

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Reaction Steps

A solution of 7-chloro-2-[(R)-3-hydroxypyrrolidine-1-carbonyl]thieno[3,2-b]pyridine 4a (1.86 g, 6.6 mmole) in THF (150 ml) was cooled to −10° prior to addition of NaH (920 mg, 23 mmole as a 60% by wt. mineral oil dispersion). The resultant mixture was stirred at 0° for 40 minutes. Iodomethane (4 ml, 9.12 g, 64 mmole) was then added to the reaction which was stirred for another 3 hours, gradually warming to room temperature. The crude reaction mixture was quenched with saturated NaHCO3 (150 ml), then extracted with EtOAc (2×100 ml). The combined organic extracts were dried over Na2SO4 and concentrated, in vacuo, to give 2.4 g of an amber paste, which was purified by silica gel chromatography. Elution with CH2Cl2: CH3OH (98:2) and evaporation of the appropriate fractions gave 1.64 g (84%) of a yellow solid. 1H NMR (DMSO-d6): δ 8.73 (1H, d, J=5.1 Hz), 8.15 (1H, s), 7.69 (1H, d, J=5.1 Hz), 4.11–3.83 (3H, m), 3.69–3.47 (2H, m), 3.27, 3.24 (3H, s), 2.18–1.93 (2H, m). Anal. Calcd. for C13H23N2O2SCl: C, 52.61; H, 4.42; N, 9.44; S, 10.80; Cl, 11.95. Found: C, 52.76; H, 4.47; N, 9.38; S, 10.84; Cl, 12.01.

Provenance & Evidence