Isopropyl chloroformate → HCID 58215555, compound

Participants

Reaction Steps

5-Fluoro-3-methyl-2-pyridin-3-yl-indole (Example 3, 0.246 g, 1.044 mmol) is dissolved in DMF (9 mL). NaH (60%, 0.054 g, 1.357 mmol) is added and the mixture is stirred for 1 h, whereupon isopropylchloroformate (1.0M in toluene 2.1 mL, 2.1 mmol) is added. The mixture is stirred overnight, quenched with saturated aqueous sodium bicarbonate and extracted with ethyl acetate. The organic phase is dried over MgSO4 and concentrated in vacuo to give a residue, which is purified by silica gel flash chromatography (ethyl acetate-heptane, 1:4 to 2:3) to give 5-fluoro-3-methyl-2-pyridin-3-yl-indole-1-carboxylic acid isopropyl ester as a pale yellow solid. 1H NMR (400 MHz, MeOD) δ ppm 1.07 (d, J=6.3 Hz, 6H), 2.12 (s, 3H), 4.93-5.04 (m, 1H), 7.09-7.17 (m, 1H), 7.30 (dd, J=8.8, 2.3 Hz, 1H), 7.54-7.59 (m, 1H), 7.84-7.89 (m, 1H), 8.23 (dd, J=9.1, 4.5 Hz, 1H), 8.53-8.56 (m, 1H), 8.61 (dd, J=4.5, 1.6 Hz, 1H). HRMS (ESI) m/z 313.1353 [(M+H)+ Calcd for C18H18FN2O2: 313.1352].

Provenance & Evidence