Methyl iodide → 2-Methylindole

The 2-bromoindole derivative 3-1 (1.009 g, 3.00 mmol, prepared as described in Example 12 of WO 03/010141) was dissolved in anhydrous THF (25 mL) under an argon atmosphere and the solution cooled to −78° C. n-BuLi (2.0 M in hexane, 1.60 mL, 3.20 mmol) was added dropwise and the mixture stirred for 15 min. MeI (0.37 mL, 2.00 mmol) was added and stirring was continued for an additional 30 min. The reaction mixture was then warmed up to RT and volatiles removed under reduced pressure. The residue was dissolved in TBME (100 mL) and the solution washed with brine (2×25 mL). The extract was dried (MgSO4), concentrated under reduced pressure and the residue purified by flash chromatography using 0–15% EtOAc in hexane as eluent. The desired 2-methylindole derivative 18-1 was obtained as a waxy solid (0.658 g, 80% yield): MS-ES m/z 272.1 (MH+). The methyl ester 18-1 was saponified in the usual way (NaOH/DMSO) to give the corresponding carboxylic acid 18-2 in 96% yield: MS-ES m/z258.1 (MH+).

1. additionwas added dropwise
2. stirringstirring
3. waitwas continued for an additional 30 min
4. customvolatiles removed under reduced pressure
5. dissolutionThe residue was dissolved in TBME (100 mL)
6. washthe solution washed with brine (2×25 mL)
7. dry with materialThe extract was dried (MgSO4)
8. concentrationconcentrated under reduced pressure
9. customthe residue purified by flash chromatography

ORD record

ord-e50a4789d6e54e039632f95f13f24e8f

Source dataset

uspto-grants-2007_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07241801B2