tert-Butyl acetate → t-Butyl 3-(2,6-dibromo-4-methoxyphenyl)-propionate

Temperature

-78 °C

To 5 mL of THF at −78° C. was added 6.5 mL of a 1.0M solution of lithium hexamethyldisilazane in THF. t-Butyl acetate (0.9 mL) was added dropwise to the resulting cold solution, and the resulting mixture was stirred for 10 min at −78° C. 2,6-Dibromo-4-methoxy-benzyl bromide (1.2 g) in 5 mL of CCl4 was added dropwise over 5 min. The mixture was stirred 20 min at −78° C., then quenched by addition of 1 mL of saturated aqueous NaHCO3. The mixture was warmed to room temperature, diluted with 50 mL of saturated aqueous NaHCO3, and extracted with 3×20 mL of EtOAc. The combined organics were washed with 25 mL of brine, dried over MgSO4, and concentrated to yield t-Butyl 3-(2,6-dibromo-4-methoxyphenyl)-propionate as an oily yellow solid. Mass spectrum (ESI) 320.9 (M-OtBu). 1H NMR (500 MHz, CDCl3): δ 7.08 (s, 2H); 3.76 (s, 3H); 3.20 (m, 2H); 2.45 (m, 2H); 1.47 (s, 9H).

1. stirringThe mixture was stirred 20 min at −78° C.
2. customquenched by addition of 1 mL of saturated aqueous NaHCO3
3. temperatureThe mixture was warmed to room temperature
4. additiondiluted with 50 mL of saturated aqueous NaHCO3
5. extractionextracted with 3×20 mL of EtOAc
6. washThe combined organics were washed with 25 mL of brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated

ORD record

ord-52ba91251cad4efc80225aee39e09e25

Source dataset

uspto-grants-2004_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06809199B2