Diethyl Oxalate → Ethyl 4-(4-chlorophenyl)-3-methyl-2,4-dioxobutanoate

HRID 1510429Notes

Reaction equation

C[Si]([N-][Si](C)(C)C)(C)C.[Li+].O1CCCC1.[CH3:16][CH2:17][C:18]([C:20]1[CH:25]=[CH:24][C:23]([Cl:26])=[CH:22][CH:21]=1)=[O:19].[C:27]([O:34][CH2:35][CH3:36])(=[O:33])[C:28]([O:30]CC)=O>C(OCC)C>[Cl:26][C:23]1[CH:22]=[CH:21][C:20]([C:18](=[O:19])[CH:17]([CH3:16])[C:28](=[O:30])[C:27]([O:34][CH2:35][CH3:36])=[O:33])=[CH:25][CH:24]=1

Participants

Conditions

Temperature: -78 °C

Procedure

A 1.0 M solution of lithium bis(trimethylsilyl)amide in tetrahydrofuran (30 mL, 30 mmol) in anhydrous diethyl ether (120 mL) under argon was cooled to −78° C. in a dry ice/acetone bath. A solution of 4-chloropropiophenone (5.0 g, 29.7 mmol) in anhydrous ether (24 mL) was added dropwise and the mixture was stirred an additional 45 minutes at −78° C. Diethyl oxalate (4.6 mL, 33.9 mmol) was added in one portion; the reaction was warmed to room temperature, and stirred overnight. The light yellow precipitate that formed was collected, washed with ether and dried under vacuum to obtain the lithium enolate of ethyl 4-(4-chlorophenyl)-3-methyl-2,4-dioxobutanoate (2.75 g, 10.0 mmol).

Workup

temperaturethe reaction was warmed to room temperature
stirringstirred overnight
customThe light yellow precipitate that formed
customwas collected
washwashed with ether
customdried under vacuum

Sources & evidence

ORD record: ord-3b5cd30040154919a6e1f47720c82fe2
Source dataset: uspto-grants-2012_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08211927B2

Reaction notes

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