Hydrochloric Acid → 5,6-Dimethoxy-2,3-dihydrobenzofuran-2-ylmethylamine

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Reaction Steps

5,6-Dimethoxy-2,3-dihydrobenzofuran-2-carbonitrile (Method 16; 2.63 g, 12.94 mmol) was dissolved in ethanol (700 ml) and hydrochloric acid (conc, 2.3 ml) and Pd on charcoal (10%, 1 g) were added. The mixture was hydrogenated under 3.5 atmosphere of hydrogen at 72° C. for 3 days. The mixture was filtered and the solvent was evaporated under reduced pressure. The residue was dissolved in water and washed once with diethyl ether. The pH of the aqueous phase was adjusted to 10–11 with NaOH(aq) and the resulting solution was extracted several times with diethyl ether, then with DCM. The organic layers were dried, filtered and evaporated under reduced pressure. The diethyl ether extraction gave 0.6 g (22%) of pure product and the DCM extraction gave 2.0 g (74%) of pure product. NMR (400 MHz) 2.80–2.87 (m, 3H), 3.21 (dd, 1H), 3.74 (s, 3H), 3.76 (s, 3H), 4.72–4.82 (m, 1H), 6.47 (s, 1H), 6.82 (s, 1H).

Provenance & Evidence