1,2-Dichloroethane → ethyl 3-tert-butyl-1-(2-morpholino-2-oxoethyl)-1H-pyrazole-5-carboxylate

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Reaction Steps

To a solution of 2-(3-tert-butyl-5-(ethoxycarbonyl)-1H-pyrazol-1-yl)acetic acid from Example B17 (0.77 g, 3.02 mmol) in DMF (5 mL) were added EDC (0.75 g, 3.93 mmol), HOBt (0.55 g, 3.62 mmol) and morpholine (0.39 g, 4.53 mmol). After stirring the mixture for 4 h at RT, water (50 mL) and 3M HCl (5 mL) were added and the product was extracted with EtOAc (3×30 mL). The combined organic layers were washed with aq. LiCl, dried (Na2SO4), concentrated and purified by chromatography (EtOAc/CH2Cl2) to afford ethyl 3-tert-butyl-1-(2-morpholino-2-oxoethyl)-1H-pyrazole-5-carboxylate (0.67 g, 69% yield) as a solid. 1H NMR (400 MHz, Acetone-d6): δ 6.74 (s, 1H), 5.40 (s, 2H), 4.27 (q, J=7.2 Hz, 2H), 3.73 (brs, 2H), 3.65-3.62 (m, 4H), 3.51 (brs, 2H), 1.32 (t, J=7.2 Hz, 3H), 1.29 (s, 9H); MS (ESI) m/z: 324.2 (M+H+).

Provenance & Evidence