Carbon Dioxide → HCID 69642170, compound

Temperature

-78 °C

A solution of 1-ethyl-7-bromoindole (2.1 g, 9.4 mmol) in THF (50 mL) was cooled to −78° C. and a 1.7 M solution of tBuLi in pentane (13.8 mL, 23.5 mmol) was added dropwise over 10 min. After 15 min, the resultant brown solution was transferred over 30 min via a cannula cooled with dry ice to a solution of dimethyl oxalate (3.88 g, 32.9 mmol) in THF (40 mL) maintained at −78° C. After 15 min, the mixture was allowed to warm to room temperature and stirred 4 h. The brown solution was treated with pH 7.0 buffer, poured into EtOAc and the EtOAc washed with pH 7.0 buffer, saturated aq NaHCO3, brine, dried (MgSO4) and concentrated to a brown oil. Flash chromatography (20% EtOAc/hexanes) afforded the title compound (1.8 g, 83%) as a yellow oil, which was used without further purification. 1H NMR (400 MHz, DMSO-d6) 7.9 (d, J=8, 1H), 7.55 (m, 2H), 7.2 (dd, J=8, 8 Hz, 1H), 6.66 (d, J=3 Hz, 1H), 4.25 (q, J=7 Hz, 2H), 3.94 (t, J=7 Hz, 3H). MS (electrospray, m/z) 232 (M++1).

1. waitthe resultant brown solution was transferred over 30 min via a cannula
2. waitAfter 15 min
3. temperatureto warm to room temperature
4. additionThe brown solution was treated with pH 7.0 buffer
5. washthe EtOAc washed with pH 7.0 buffer
6. dry with materialsaturated aq NaHCO3, brine, dried (MgSO4)
7. concentrationconcentrated to a brown oil

ORD record

ord-bb6a3e983b29493a8c0c1d3781ebebd4

Source dataset

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07109229B2