Isatin → 1-(3-methylbutyl)-1H-indole-2,3-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of isatin (4.41 g, 30 mmol) in DMF (60 mL) at 0° C. was added 60% NaH (1.50 g, 37.5 mmol) portionwise. After addition, the resulting mixture was stirred for 15 min at 0° C. and 1-bromo-3-methylbutane (4.7 mL, 37.5 mmol) was added dropwise over 2 min. The resulting mixture was stirred for 1 h at 0° C. followed by 6 h at rt. The reaction was cooled to 0° C., quenched with sat. NH4Cl, ice, H2O, extracted with EtOAc (200 mL×2), dried over Na2SO4 and concentrated to give crude 1-isopentylisatin as a dark orange red liquid which was used without further purification. 1H NMR (400 MHz, DMSO-d6) δ 7.66 (t, J=7.6 Hz, 1H), 7.54 (d, J=7.2 Hz, 1H), 7.15 (d, J=8.8 Hz, 1H, partially overlapping with the peak at 7.12 ppm), 7.12 (t, J=7.6 Hz, 1H, partially overlapping with the peak at 7.15 ppm), 3.66 (t, J=7.6 Hz, 2H), 1.67-1.57 (m, 1H), 1.48 (q, J=7.2 Hz, 1H), 0.92 (d, J=6.4 Hz, 6H); MS ESI 217.9 [M+H]+, calcd for [C13H15NO2+H]+ 218.1.

Provenance & Evidence