Diethyl Oxalate → Ethyl 2-(3,5-dichloro-2,6-dimethoxypyridin-4-yl)-2-oxoacetate

HRID 1375408Notes

Reaction equation

[Cl:1][C:2]1[C:3]([O:11][CH3:12])=[N:4][C:5]([O:9][CH3:10])=[C:6]([Cl:8])[CH:7]=1.[Li+].CC([N-]C(C)C)C.[C:21](OCC)(=[O:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23].[Cl-].[NH4+]>C1COCC1>[Cl:8][C:6]1[C:5]([O:9][CH3:10])=[N:4][C:3]([O:11][CH3:12])=[C:2]([Cl:1])[C:7]=1[C:21](=[O:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23]

Participants

Conditions

Temperature: -78 °C

Procedure

A solution of 5.20 g (25 mmol) of 3,5-dichloro-2,6-dimethoxypyridine (J. Bratt, H. Suschitzky, J.C.S. Perkin I, 1983:1689–1693) in 40 mL THF is added dropwise over 30 minutes to a solution of 20 mL (30 mmol) of 1.5 M LDA in 20 mL THF at −78° C. The resulting solution is stirred at −78° C. for 1 hour, and 4.5 mL (33 mmol) of diethyl oxalate is then added. The temperature is allowed to rise slowly to room temperature and aqueous ammonium chloride solution is added, and the solvent is removed under vacuum. The residue is extracted into EtOAc and chromatographed on SiO2, eluting with hexane-EtOAc (9:1), to give 5.97 g (78%) of the title compound: mp (hexane) 195–196° C.

Workup

customto rise slowly to room temperature
customthe solvent is removed under vacuum
extractionThe residue is extracted into EtOAc
customchromatographed on SiO2
washeluting with hexane-EtOAc (9:1)

Sources & evidence

ORD record: ord-1c76a0564a4b4b7a929680bd5d8bde0a
Source dataset: uspto-grants-2007_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07169778B2

Reaction notes

Loading…