4-Cyanopyridine → 4-(3,4-Dimethoxybenzoyl)pyridine

Participants

Reaction Conditions

Reaction Steps

A hexane solution of butyl lithium (9 mL, 22 mmol, 2.5 M) was slowly added to a stirring solution of 4-bromoveratrole (2.9 mL, 20 mmol) in 40 mL of tetrahydrofuran under nitrogen at −70° C. After 15 minutes a solution of 4-cyanopyridine in 12 mL of tetrahydrofuran was added to the reaction mixture and stirring was continued for 45 minutes. The reaction was then allowed to warm to −10° C. and the reaction was carefully quenched with hydrochloric acid (45 mL, 1 N). The mixture was stirred for 30 minutes at room temperature. The pH was then adjusted to 12 with 50 mL of a 10% aqueous solution of sodium hydroxide. The mixture was extracted with ether (3×50 mL). The combined ethereal extracts were washed with brine (100 mL) then dried over magnesium sulfate and concentrated in vacuo to a brown solid. The crude product was purified by flash column chromatography (silica gel, 3% methanol/methylene chloride) to afford after vacuum drying (60° C., 1 mm) 1.9 g (39%) of the product: mp 117-118° C.; 1H NMR (CDCl3) δ 8.85-8.76 (m, 2 H), 7.60-7.50 (m, 3 H), 7.40-7.30 (m, 1 H), 6.97-6.88 (m, 1 H), 3.98 (s, 3 H), 3.96 (s, 3 H); 13C NMR (CDCl3) δ 193.7, 153.9, 150.1, 149.3, 145.2, 128.7, 125.9, 122.6, 111.5, 109.9, 56.1, 56.0; Anal. Calcd for C14H13NO3. Theoretical: C, 69.12; H, 5.39; N, 5.76. Found: C, 69.05; H, 5.39; N, 5.85.

Provenance & Evidence