2-Bromopropane → HCID 86757158, compound

Temperature

-78 °C

To a stirred solution of 5.0 g (25.0 mmol) trans-2-butene-1,4dicarboxylic acid diethyl ester in 120 ml THf was added 6.35 g (150 mmol) anhydrous lithium chloride and the resulting suspension cooled to −78° C. 25.0 ml (50.0 mmol) of a 2 M solution of LDA in THF was added dropwise and stirring continued for 45 min. 4.7 ml (50 mmol) isopropyl bromide was then added and stirring continued for 15 min at −78° C., then 4 h at 0° C., and then 48 h at room temperature. The reaction was quenched by addition of saturated ammonium chloride solution and the mixture extracted three times with ether. The combined organic phases were washed successively with saturated ammonium chloride solution, water, and saturated brine, dried over sodium sulphate, and concentrated in vacuo. Successive flash chromatography (20% EtOAc in hexane for first column; 5% EtOAc in hexane for second column; 10% EtOAc in hexane for third column) afforded 259 mg (4%) of the title compound as a yellow oil. MS m/e (%): 302 ([M+NH4]+, 100).

1. stirringstirring
2. waitcontinued for 15 min at −78° C.
3. custom4 h
4. customat 0° C.
5. custom48 h
6. customat room temperature
7. customThe reaction was quenched by addition of saturated ammonium chloride solution
8. extractionthe mixture extracted three times with ether
9. washThe combined organic phases were washed successively with saturated ammonium chloride solution, water, and saturated brine
10. dry with materialdried over sodium sulphate
11. concentrationconcentrated in vacuo

ORD record

ord-d8881ad2493949c9b3f5120be5bbfc52

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06262089B1