Methyl iodide → 2-(3-Bromophenyl)-2-methylpropanoic acid

To a solution of lithium diisopropylamide in tetrahydrofuran/n-heptane/ethylbenzene (1.8 M, 17 mL) at 0° C. is added a solution of 2-(3-bromo-phenyl)-propionic acid (3 g, 13.9 mmol) in tetrahydrofuran (5 mL) dropwise during 15 minutes. The mixture is stirred for 1 hour, followed by addition of methyl iodide (4.93 g, 34.8 mmol) in tetrahydrofuran (5 mL) dropwise during 10 min. The reaction mixture is stirred for 15 hours, quenched with 2 N HCl, concentrated in vacuo, and diluted with ether (150 mL). The ether layer is washed with 2 N HCl, extracted three times with 2 N NaOH (50 mL). The combined NaOH layers are acidified with 6 N HCl to pH=1 and extracted three times with ether (75 mL). The combined organic layers are washed with brine, dried over sodium sulfate and concentrated to obtain 2-(3-bromo-phenyl)-2-methyl-propionic acid as a solid (3.08 g, 91%), which is used without further purification. LC/MS: 243 (M+H).

1. stirringThe reaction mixture is stirred for 15 hours
2. customquenched with 2 N HCl
3. concentrationconcentrated in vacuo
4. additiondiluted with ether (150 mL)
5. washThe ether layer is washed with 2 N HCl
6. extractionextracted three times with 2 N NaOH (50 mL)
7. extractionextracted three times with ether (75 mL)
8. washThe combined organic layers are washed with brine
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated

ORD record

ord-5eb2e6ec1fab479cb79ae5bf17d30528

Source dataset

uspto-grants-2010_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07642249B2