Hydrochloric Acid → 5-isopropyl-2-methyl-benzaldehyde

HRID 472024Notes

Reaction equation

Br[C:2]1[CH:7]=[C:6]([CH:8]([CH3:10])[CH3:9])[CH:5]=[CH:4][C:3]=1[CH3:11].[Li]C(C)(C)C.CN([CH:20]=[O:21])C.Cl>C1COCC1.CCCCC.C(OCC)C>[CH:8]([C:6]1[CH:5]=[CH:4][C:3]([CH3:11])=[C:2]([CH:7]=1)[CH:20]=[O:21])([CH3:10])[CH3:9]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of 2-bromo-4-isopropyl-1-methyl-benzene (863 mg, 4.0 mmol) in 10 mL of THF is added a solution of t-BuLi (1.7 M in pentane, 4.7 mg dropwise at below −70° C. After addition, the reaction mixture is stirred at −78° C. for one hour. A solution of DMF (0.46 mL) in 1 mL of THF is added at the same temperature and stirred for additional one hour. The reaction mixture is allowed to warm to room temperature then poured into a mixture containing ice (50 g) and concentrated HCl (2 mL) and stirred for 15 minutes. To the mixture, ethyl ether (20 mL) is added. The organic layer is separated and the aqueous layer is extracted with ethyl ether. The organic solutions are combined, washed with brine, dried and concentrated to give 600 mg of 5-isopropyl-2-methyl-benzaldehyde. 1H NMR: (CDCl3) 10.27 (s, 1H), 7.66 (d, 1H), 7.34 (d, 1H), 7.17 (d, 1H), 2.94 (m, 1H), 2.63 (s, 3H), 1.24 (d, 6H).

Workup

customdropwise at below −70° C
additionAfter addition
stirringstirred for additional one hour
temperatureto warm to room temperature
additionthen poured into a mixture
stirringstirred for 15 minutes
customThe organic layer is separated
extractionthe aqueous layer is extracted with ethyl ether
washwashed with brine
customdried
concentrationconcentrated

Sources & evidence

ORD record: ord-9d8ae583ae664ed0808b74bfe2df5461
Source dataset: uspto-grants-2014_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08633193B2

Reaction notes

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