Potassium Carbonate → methyl 5-((4-fluorophenyl)ethynyl)-2-methyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole-8-carboxylate

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Reaction Conditions

Reaction Steps

Methyl 2,3,4,5-tetrahydro-2-methyl-1H-pyrido[4,3-b]indole-8-carboxylate (122 mg, 0.5 mmol) was dissolved in toluene (3 mL) and stirred for 10 min. Potassium carbonate (138 mg, 1.0 mmol), copper sulfate (124 mg, 0.05 mmol) and 1,10-phenanthraline (18 mg, 0.1 mmol) were added. The reaction mixture was stirred for 10 min. A solution of 1-(bromoethynyl)-4-fluorobenzene (110 mg, 0.11 mmol) in toluene (2 mL) was added to the reaction mixture, which was heated to 80-85° C. overnight. TLC monitoring showed 10% conversion of reactant to product. As such, more of 1-(bromoethynyl)-4-fluorobenzene (110 mg, 0.5 mmol) was added and heating was continued for 10-12 h. Toluene was removed under reduced pressure to obtain the product, which was purified by column chromatography using silica (100-200 mesh) and 0-5% DCM:MeOH as eluent. The pure compound was converted to its oxalate salt. 1H NMR (CD3OD, oxalate salt) δ (ppm): 8.30 (d, 1H), 8.05 (m, 1H), 7.78 (d, 1H), 7.62 (m, 2H), 7.20 (m, 2H), 3.95 (s, 3H), 3.80 (m, 2H), 3.70 (m, 2H), 3.35 (m, 2H), 3.15 (s, 3H).

Provenance & Evidence