1,1-Dibromoethane → HCID 15044971, compound

HRID 728064Notes

Reaction equation

[Na].[CH3:2][O:3][C:4]1[CH:5]=[C:6]([CH:14]([C:20]#[N:21])[C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:7]=[C:8]([O:12][CH3:13])[C:9]=1[O:10][CH3:11].[Br:22][CH:23](Br)[CH3:24]>C(O)C>[CH3:13][O:12][C:8]1[CH:7]=[C:6]([C:14]([CH2:24][CH2:23][Br:22])([C:20]#[N:21])[C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:5]=[C:4]([O:3][CH3:2])[C:9]=1[O:10][CH3:11]

Participants

Conditions

Temperature: 90 °C

Procedure

To dry ethanol (100 ml) under a nitrogen atmosphere was added sodium (4.2 gm, 0.18 mol). After the sodium had completely dissolved, ethyl 3,4,5-trimethoxy-α-cyanobenzeneacetate (50.0 g, 0.18 mol) in ethanol (70 ml) was added dropwise over 30 minutes. A slight exotherm was observed. The reaction was heated to 90° C. for 30 minutes, then added dropwise over 2 hours to a refluxing solution of dibromoethane (340.0 g, 1.8 mol) in ethanol (500 ml). The reaction was refluxed an additional 3 hours, then concentrated. The residue was taken up in water (300 ml) and extracted with ethyl acetate (2×500 ml). The combined organic layers were washed with brine (1×100 ml), dried (MgSO4) and concentrated to a solid. The solid was washed with hexane (3×200 ml) then recrystallized from hexane to give ethyl 3,4,5-trimethoxy-α-(2-bromoethyl)-α-cyanobenzeneacetate in 65% yield as a white solid, m.p. 76°-77° C.

Workup

temperatureThe reaction was refluxed an additional 3 hours
concentrationconcentrated
extractionextracted with ethyl acetate (2×500 ml)
washThe combined organic layers were washed with brine (1×100 ml)
dry with materialdried (MgSO4)
concentrationconcentrated to a solid
washThe solid was washed with hexane (3×200 ml)
customthen recrystallized from hexane

Sources & evidence

ORD record: ord-28a71193147f46d0bf2aecd92085363e
Source dataset: uspto-grants-1991_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05047420

Reaction notes

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