Potassium Phosphate, Tribasic → (E)-2,3,8-trimethyl-5-(2-(6-methylpyridin-3-yl)prop-1-enyl)-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole

Participants

Reaction Steps

2,3,8-Trimethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (107 mg, 0.5 mmol) was dissolved in DMF. Copper (I) iodide (9.5 mg, 0.05 mmol), L-proline (11.5 mg, 0.1 mmol) and potassium phosphate (414 mg, 2 mmol) were added and the reaction mixture was stirred for 10 min. at RT. 5-(2-bromovinyl)-2-methylpyridine (116 mg, 0.55 mmol) was added dropwise and the reaction mixture was purged with nitrogen. The reaction mixture was heated overnight at 100° C. (prolonged heating in some cases was required). DMF was evaporated under reduced pressure, the residue was diluted with water and the solid was filtered. The solid material was purified by silica gel chromatography (100-200 mesh) eluting with 0-7% MeOH-DCM. Yield: 125 mg. 1H NMR (CD3OD, oxalate salt) δ (ppm): 8.78 (s, 1H), 8.22 (d, 1H), 7.90 (s, 1H), 7.58 (d, 1H), 7.30 (s, 1H), 7.18 (d, 1H), 7.10 (d, 1H), 4.60 (m, 2H), 4.0 (m, 1H), 3.30 (m, 1H), 3.05 (m, 3H), 2.95 (m, 1H), 2.65 (s, 3H), 2.42 (s, 3H), 2.0 (s, 3H), 1.50 (d, 3H).

Provenance & Evidence