Dimethylformamide → 4-Cyclopropylbenzaldehyde

Temperature

-78 °C

To a solution of 1-bromo-4-cyclopropylbenzene [synthesized in analogy to a procedure described in J. Org. Chem. 41:2262-2266 (1976)] (1.58 g, 8.04 mmol) in THF at −78° C. was added n-BuLi (5.08 ml, 1.6M solution in hexane, 8.11 mmol) and the reaction mixture was stirred at −78° C. for 10 min. DMF (1.25 ml, 16.08 mmol) was then added and the reaction mixture was stirred at −78° C. for 15 min. The reaction mixture was then warmed to 0° C. slowly (over 2 h) and stirred at 0° C. for 1 h. The reaction was quenched with sat. NH4Cl (aq) solution and the aqueous phase was extracted with ether. The organic layer was washed with brine, dried (MgSO4), filtered and concentrated in vacuo to give a residue which was purified by flash column chromatography (1:9 diethylether:pentane) to give 4-cyclopropyl benzaldehyde (1.10 g, 94%) as a colorless oil. 1H NMR (CDCl3, 300 MHz): δ 9.94 (s, 1H), 7.76 (d, J=8.5 Hz, 2H), 7.19 (d, J=8.5 Hz, 2H), 1.97 (m, 1H), 1.13-1.06 (m, 2H), 0.84-0.78 (m, 2H).

1. stirringthe reaction mixture was stirred at −78° C. for 15 min
2. temperatureThe reaction mixture was then warmed to 0° C. slowly (over 2 h)
3. stirringstirred at 0° C. for 1 h
4. customThe reaction was quenched with sat. NH4Cl (aq) solution
5. extractionthe aqueous phase was extracted with ether
6. washThe organic layer was washed with brine
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customto give a residue which
11. customwas purified by flash column chromatography (1:9 diethylether:pentane)

ORD record

ord-5b3238df35fe4d53b15f90e2dcc04eff

Source dataset

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07259183B2