Methyl Acrylate → 1-(2-Methoxycarbonyl-ethyl)-3-(4-trifluoromethyl-phenyl)-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

3-(4-Trifluoromethyl-phenyl)-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester (1.85 g, 5.04 mmol) and methyl acrylate (0.50 mL, 5.6 mmol) were combined in toluene (30 mL) and heated to 75° C. The resulting mixture was treated with t-BuONa (100 mg), and heating continued for 48 h. The mixture was allowed to cool and partitioned between EtOAc (300 mL) and NaHCO3 (75 mL). The aqueous layer was extracted with EtOAc (3×75 mL). The combined extracts were dried over Na2SO4 and concentrated. Column chromatography (silica, 30-60% EtOAc/hexanes) afforded 343 mg (15%) of the title compound. TLC (silica, 50% EtOAc/hexanes): Rf=0.4. MS (electrospray): m/z calculated for C22H27F3N3O4 [M++H] 454.20. found 454.1. 1H NMR (CDCl3, 400 MHz): 7.75 (br d, J=8.1 Hz, 2H), 7.64 (br s, 2H), 4.63 (br s, 2H), 4.30 (t, J=6.6 Hz, 2H), 3.75 (br s, 2H), 3.68 (s, 3H), 2.98 (t, J=6.6 Hz, 2H), 2.79 (br t, J=5.6 Hz, 2H), 1.48 (s, 9H).

Provenance & Evidence