Methyl iodide → tert-Butyl 7-bromo-5-methyl-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate

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Reaction Steps

Sodium hydride (60% weight dispersion in mineral oil, 4.19 g, 0.105 mol) was added portionwise to a solution of tert-butyl 7-bromo-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate (23.6 g, 0.07 mol) in DMF (300 mL) at room temperature under N2. After 1 h, methyl iodide (14.8 g, 6.47 mL, 0.105 mol) was added, and the reaction was allowed to proceed for an additional 2 h. The mixture was quenched with H2O, upon which a solid precipitated out of solution. The suspension was therefore diluted to 2 L with H2O and filtered. The solids were washed thoroughly with water, then dissolved in CH2Cl2, dried over Na2SO4, filtered and concentrated to dryness. This provided the title compound (22.4 g, 91%) as a yellow solid: 1H NMR (300 MHz, CDCl3) δ 7.41 (s, 1H), 7.30 (d, J=8.3 Hz, 1H), 7.17 (d, J=8.4 Hz, 1H), 4.60 (s, 2H), 3.81 (br t, 2H), 3.58 (s, 3H), 2.77 (t, J=5.4 Hz, 2H), 1.50 (s, 9H).

Provenance & Evidence