Succinic anhydride → 4-(1-Dimethylaminomethyl-1H-benzoimidazole-5-carbonyl)-piperazine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

To stirring solution of 1 (1.50 g, 4.54 mmol) in dichloromethane (20 mL) was added potassium carbonate (690 mg, 4.99 mmol, 1.1 eq) and succinic anhydride (500 mg, 4.99 mmol, 1.1 eq) at 23° C. Next, N,N,N′,N′-tetramethylamino methane (0.68 mL, 4.99 mmol, 1.1 eq) was added dropwise and the suspension stirred at room temperature for 6 hr. The reaction mixture was diluted with dichloromethane (50 mL) and quenched with 20% NaOH (aq) (50 mL). The layers were separated and the organic washed with water, dried over Na2SO4, and concentrated to an off white solid (1.76 g, 4.74 mmol, 100%). 1H NMR (CDCl3, 400 MHz): δ 7.94 (s, 1H), δ 7.79-7.71 (m, 1H), δ 7.60 (s, 0.5H), δ 7.50-7.48 (d, 0.5H), δ 7.38-7.35 (d, 0.5H), δ 7.25-7.22 (d, 0.5H), δ 4.80-4.78 (d, 2H), δ 3.80-3.35 (m, 8H), δ 2.28 (s, 6H), δ 1.41 (s, 9H)

Herkunft & Nachweise