2-Methyl-1,2,3,4-tetrahydro-beta-carboline → 4-(2-Methyl-1,2,3,4-tetrahydro-b-carbolin-9-ylmethyl)benzoic acid methyl ester

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Reaction Conditions

Reaction Steps

A round bottom flask fitted with reflux condenser containing 2-methyl-2,3,4,9-tetrahydro-1H-b-carboline (16) (0.30 g, 1.62 mmol) and potassium tert-butoxide (0.22 g, 1.92 mmol) was vacuum purged and filled with argon, followed by addition of DMSO (5 mL). After stirring at 120° C. for 20 min, 4-bromomethyl-benzoic acid methyl ester (0.37 g, 1.62 mmol) was added and the mixture was stirred at 120° C. for 3 h. The reaction was quenched by addition of water (30 mL), transferred to a separatory funnel and extracted with ethyl acetate (3×20 mL). The combined organic layers were washed with brine (2×20 mL), dried (Na2SO4) and concentrated. The product was purified by MPCC (0 to 5% gradient of MeOH in CH2Cl2), which gave 180 mg (33%) of the title compound. 1H NMR (400 MHz, CDCl3): δ 7.95 (d, 2H, J=8.2 Hz), 7.54 (m, 1H, J=7.6 Hz), 7.18-7.11 (m, 4H), 7.15 (d, 2H, J=8.1 Hz), 5.25 (s, 2H), 3.89 (s, 3H), 3.53 (s, 2H), 2.90 (m, 2H), 2.80 (m, 2H), 2.51 (s, 3H). 13C NMR (100 MHz, CDCl3): δ 166.5, 141.9, 137.4, 130.4, 126.0, 122.8, 120.2, 118.6, 109.4, 106.7, 52.2, 51.3, 49.7, 46.6, 45.56, 42.1, 18.5. ESI-HRMS (m/z): [M+H]+ calcd. for C21H22N2O2, 335.1727. found, 335.1724.

Provenance & Evidence