Potassium Carbonate → (S)-Ethyl 1-((2-(benzyloxycarbonylamino)-2,3-dihydro-1H-inden-5-yl)methyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate

関与物質

反応手順

(S)-Benzyl 5-(hydroxymethyl)-2,3-dihydro-1H-inden-2-ylcarbamate (2.96 mmol, 880 mg) was dissolved in DCM (10 mL) and thionyl chloride (5.92 mmol, 0.432 ml, 704 mg) added. The mixture was stirred at room temperature for 30 min TLC before the solvent was removed under reduced pressure and residual thionylchloride azeotroped with DCM (×3). To the residue was added potassium carbonate (8.88 mmol, 1227 mg) followed by DMF (8 ml) then ethyl 3-(trifluoromethyl)-1H-pyrazole-4-carboxylate (2.96 mmol, 616 mg) and the mixture heated to 60° C. After 1 h the mixture was concentrated and partitioned between EtOAc/H2O and the organic layer was washed with water (×3). The organic layer was dried, filtered and concentrated to give a yellow oil which was purified by flash chromatography eluting with 15% EtOAc/Heptane to give the desired isomer as a colourless oil (45 mg, 0.092 mmol, 3.1%). 1H NMR (400 MHz, CDCl3) δ 1.34 (t, 3H) 2.75 (m, 2H) 3.25 (m, 2H) 4.33 (q, 2H), 4.50 (m, 1H) 4.95 (m, 1H), 5.08 (s, 2H) 5.48 (s, 2H) 7.00 (m, 2H) 7.15 (d, 1H) 7.34 (m, 5H) 7.99 (s, 1H).

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