Dimethylamine, hydrochloride → Ethyl 4-cyano-3-[1-(3,4-dichlorophenyl)-3-(dimethylamino)propyl]-5-(morpholin-4-yl)thiophene-2-carboxylate

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Reaction Steps

To a solution of ethyl 4-cyano-3-[1-(3,4-dichlorophenyl)-3-oxopropyl]-5-(morpholin-4-yl)thiophene-2-carboxylate (38.0 mg, 0.0813 mmol) (from example 56, step 1) in methanol (1.00 mL) was added dimethylamine hydrochloride (9.94 mg, 0.122 mmol), sodium acetate (8.00 mg, 0.0976 mmol), and sodium cyanoborohydride (6.13 mg, 0.0976 mmol). The reaction was stirred at rt for 2 h. The mixture was distributed between NaHCO3(aq) saturated solution and EtOAc. The aqueous layer was extracted with EtOAc (×2). The combined organic layer was dried and concentrated. Purification on a silica gel column (gradient elution, 0-15% MeOH/CH2Cl2) provided ethyl 4-cyano-3-[1-(3,4-dichlorophenyl)-3-(dimethylamino)propyl]-5-(morpholin-4-yl)thiophene-2-carboxylate as a yellow syrup (29.0 mg, 71.8% yield). LCMS: (AA) ES+ 496, 498, 500; 1H NMR (400 MHz, CDCl3) δ 7.52-7.44 (d, J=1.9 Hz, 1H), 7.41-7.34 (m, 1H), 7.33-7.27 (m, 1H), 5.54-5.40 (t, J=7.7 Hz, 1H), 4.38-4.27 (q, J=7.1 Hz, 2H), 3.88-3.76 (t, J=4.9 Hz, 4H), 3.58-3.49 (dd, J=5.7, 4.0 Hz, 4H), 2.57-2.31 (m, 3H), 2.29-2.24 (s, 6H), 2.24-2.16 (m, 1H), 1.41-1.30 (t, J=7.1 Hz, 3H).

Provenance & Evidence