Hydrochloric Acid → 3-(5-Chloro-thiophen-2-yl)-3-oxo-propionic acid tert-butyl ester

HRID 1433041Notes

Reaction equation

[C:1]([O:4][C:5]([CH3:8])([CH3:7])[CH3:6])(=[O:3])[CH3:2].C[Si]([N-][Si](C)(C)C)(C)C.[K+].[Cl:19][C:20]1[S:24][C:23]([C:25](OCC)=[O:26])=[CH:22][CH:21]=1.Cl>C1COCC1.C1(C)C=CC=CC=1>[C:5]([O:4][C:1](=[O:3])[CH2:2][C:25]([C:23]1[S:24][C:20]([Cl:19])=[CH:21][CH:22]=1)=[O:26])([CH3:8])([CH3:7])[CH3:6]

Participants

Conditions

Temperature: 0 °C

Procedure

A 0.25M THF solution of tert-butyl acetate (2.90 g, 25 mmol) is added dropwise to a cold (−78° C.) solution of potassium bis(trimethylsilyl)amide (100 ml of a 0.5M toluene solution) and ethyl 5-chlorothiophene-2-carboxylate (Lancaster)(4.77 g, 25 mmol) in 50 ml of THF. The reaction is allowed to warm to 0° C. over one hour. After stirring an additional hour at 0° C., the reaction is poured into 100 ml of a 1M HCl solution. The organic layer is extracted with brine and evaporated in vacuo. The crude residue is purified by flash column chromatography eluting with 5% ethyl acetate/hexane to provide the product (4.54 g, 17 mmol) as an oil. 1H NMR (CDCl3, 300 MHz) δ7,53 (d, 1H), 6.98 (d, 1H), 3.78 (3, 2H), 1.50 (s, 9H).

Workup

extractionThe organic layer is extracted with brine
customevaporated in vacuo
customThe crude residue is purified by flash column chromatography
washeluting with 5% ethyl acetate/hexane

Sources & evidence

ORD record: ord-3b01ad5f24ac4a9090eb335691ad5b1e
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07612075B2

Reaction notes

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