Hydrochloric Acid → HCID 59199405, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 3,2-dimethyl-1,1-dioxo-2,3-dihydro-1H-1lambda*6*-benzo[b]thiophen-3-ol (3.1 g, 14.6 mmol) in THF (100 mL) is added methyl 4-imidazolecarboxylate (CAS#17325-26-7, 2.76 g, 2.1.9 mmol), and triphenylphosphine (5.73 g, 21.9 mmol). The reaction is cooled to 0° C. and di-t-butyl azodicarboxylate (5.04 g, 21.9 mmol) is added. The reaction is placed at room temperature and permitted to stir for three hours. The reaction mixture is cooled to 0° C. and quenched with 4 N HCl in dioxane (5 mL, 20 mmol) and stirred for 30 minutes. The reaction is concentrated to near dryness and diluted with ethyl acetate. The organic layer is extracted three times with 1 N aqueous HCl. The aqueous extracts are combined, neutralized with Na2CO3, and extracted three times with ethyl acetate. The combined organic layers are dried with Na2SO4, filtered, and concentrated. The resulting residue is purified by silica gel flash chromatography (ethyl acetate-dichloromethane, 0:1 to 3:7) to furnish 3-(2,2-dimethyl-1,1-dioxo-2,3-dihydro-1H-1lambda*6*-benzo[b]thiophen-3-yl)-3H-imidazole-4-carboxylic acid methyl ester; MS: (ESI) m/z 321 (M+H)+; 1H NMR: (400 MHz, CDCl3) δ ppm 1.18 (s, 3 H), 1.62 (s, 3 H), 3.96 (s, 3 H), 6.69 (s, 1 H), 7.29 (s, 1 H), 7.38-7.46 (m, 1 H), 7.68-7.76 (m, 2 H), 7.84 (s, 1 H), 7.91-7.97 (m, 1 H).

Provenance & Evidence