Diethyl Carbonate → Ethyl 2-(4-broMopyridin-2-yl)acetate

HRID 1528600Notes

Reaction equation

C([N-]C(C)C)(C)C.[Li+].[Br:9][C:10]1[CH:15]=[CH:14][N:13]=[C:12]([CH3:16])[CH:11]=1.[C:17](=O)([O:21]CC)[O:18][CH2:19][CH3:20]>O1CCCC1>[CH2:19]([O:18][C:17](=[O:21])[CH2:16][C:12]1[CH:11]=[C:10]([Br:9])[CH:15]=[CH:14][N:13]=1)[CH3:20]

Participants

Conditions

Temperature: -70 °C

Procedure

Lithium diisopropylamide (2 mol/L in tetrahydrofuran/heptane/ethylbenzene, 3.00 mL) was added to a solution of 4-bromo-2-methylpyridine (2.00 g) and diethyl carbonate (1.8 mL) in tetrahydrofuran (30 mL) cooled to −70° C. The solution was stirred for 1 h prior to the addition of another portion of lithium diisopropylamide (2 mol/L in tetrahydrofuran/heptane/ethylbenzene, 3.00 mL). Stirring was continued at −70° C. for one more hour and then the reaction was quenched by the addition of water. The resulting mixture was extracted with ethyl acetate and the combined extracts were washed with brine and dried (Na2SO4). The solvent was evaporated and the residue was chromatographed on silica gel (cyclohexane/ethyl acetate 95:5→1:1) to give the title compound. Yield: 2.35 g (83% of theory); LC (method 3): tR=2.86 min; Mass spectrum (ESI+): m/z=244/246 (Br) [M+H]+.

Workup

stirringStirring
customwas continued at −70° C. for one more hour
customthe reaction was quenched by the addition of water
extractionThe resulting mixture was extracted with ethyl acetate
washthe combined extracts were washed with brine
dry with materialdried (Na2SO4)
customThe solvent was evaporated
customthe residue was chromatographed on silica gel (cyclohexane/ethyl acetate 95:5→1:1)

Sources & evidence

ORD record: ord-1c34bf2c51354f6f8072399987444e41
Source dataset: uspto-grants-2015_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09090605B2

Reaction notes

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