Hydrochloric Acid → Ethyl 2-azido-3-(2-thienyl)propenoate

HRID 1713038Notes

Reaction equation

[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH:6]=O.[N:8]([CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])=[N+:9]=[N-:10].[O-]CC.[Na+].Cl>C1(C)C=CC=CC=1.C(O)C>[CH2:15]([O:14][C:12](=[O:13])[C:11]([N:8]=[N+:9]=[N-:10])=[CH:6][C:2]1[S:1][CH:5]=[CH:4][CH:3]=1)[CH3:16]

Participants

Conditions

Temperature: 10 °C

Procedure

A solution of thiophene-2-carbaldehyde (650 mg, 5.8 mmol) and ethyl azidoacetate (6.89 grams, 53.4 mmol) in dry toluene (40 ml) was added to a cold (−5° C.) solution of sodium ethoxide (about 53 mmol) in ethanol (60 ml) during a time period of one hour, under nitrogen atmosphere. Stirring was continued for another hour while maintaining the temperature under 10° C. The reaction mixture was then cooled to 0° C. and acidified with HCl 0.1 M. After separation of the phases, the aqueous phase was extracted with ether (3×30 ml), the combined organic phase was dried over Na2SO4 and the organic solvents were evaporated under reduced pressure. The crude product was purified by silica gel flash chromatography to give 718 mg of pure 2-azido-3-thiophen-2-yl-acrylic acid ethyl ester (55% yield).

Workup

waitwas continued for another hour
temperatureThe reaction mixture was then cooled to 0° C.
customAfter separation of the phases
extractionthe aqueous phase was extracted with ether (3×30 ml)
dry with materialthe combined organic phase was dried over Na2SO4
customthe organic solvents were evaporated under reduced pressure
customThe crude product was purified by silica gel flash chromatography

Sources & evidence

ORD record: ord-e4d06ddd0a6b4803a97cd2fea85b60c0
Source dataset: uspto-grants-2010_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07795255B2

Reaction notes

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