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

HRID 1466295Notes

Reaction equation

[NH:1]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:4](=[O:5])[C:2]1=[O:3].[H-].[Na+].Br[CH2:15][CH2:16][CH:17]([CH3:19])[CH3:18]>CN(C=O)C>[CH2:15]([N:1]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:4](=[O:5])[C:2]1=[O:3])[CH2:16][CH:17]([CH3:19])[CH3:18]

Participants

Conditions

Temperature: 0 °C

Procedure

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.

Workup

additionAfter addition
stirringThe resulting mixture was stirred for 1 h at 0° C.
waitfollowed by 6 h at rt
temperatureThe reaction was cooled to 0° C.
customquenched with sat. NH4Cl, ice, H2O
extractionextracted with EtOAc (200 mL×2)
dry with materialdried over Na2SO4
concentrationconcentrated

Sources & evidence

ORD record: ord-70f526823e094e9c95828536eaf0c266
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08999968B2

Reaction notes

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