Hydrochloric Acid → Dimethyl 3-cyanobenzene-1,2-dicarboxylate

Beteiligte Stoffe

Reaktionsschritte

To a stirred suspension of methyl-3-amino-2-(methoxycarbonyl)benzoate (17.0 g, 81 mmol) in a mixture of concentrated HCl (44 ml) and water (440 ml) at 4° C. was added a solution of NaNO2 (6.73 g, 97 mmol) in water (25 ml) dropwise at 4–5° C. Stirring was continued for 30 min at 4° C. The mixture was then carefully neutralized with sat. sodium carbonate to pH 6. A stirred solution of CuCN (9.46 g, 105 mmol) and KCN (6.38 g, 105 mmol) in water (150 ml) was warmed to 60° C. The cold neutralized diazonium solution was then added in small portions at a time with vigorous stirring. The mixture was stirred at 60° C. for 1 hour and then cooled to room temperature. The mixture was extracted with dichloromethane (4×150 ml) and the combined dichloromethane extracts were washed with water (2×100 ml), brine (100 ml) and dried. The solvent was removed in vacuo and the product was purified by chromatography (dichloromethane) to afford 12.36 g (65%) of the product as a light yellow solid: 1H NMR (CDCl3) δ 8.19 (d, J=7.9 Hz, 1H), 7.89 (d, J=7.4 Hz, 1H), 7.64 (t, J=8.0 Hz, 1H), 4.03 (s, 3H), 3.94 (s, 3H).

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