Ethyl Bromide → (5Z)-5-Hexadecene

HRID 861707Notes

Reaction equation

[Mg].[CH2:2](Br)[CH3:3].Cl[CH2:6][CH2:7]/[CH:8]=[CH:9]\[CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH3:19].[Cl-].[NH4+]>O1CCCC1>[CH3:6][CH2:7][CH2:8][CH2:9]/[CH:10]=[CH:11]\[CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:2][CH3:3]

Participants

Conditions

Temperature: 0 °C

Procedure

A 1-liter reactor was charged with 5.0 g (0.206 mole) of magnesium and 90 g of tetrahydrofuran, and the reaction was initiated by adding 2 g of ethyl bromide and 46 g (0.2 mole) of 1-chloro-cis-3-tetradecene dropwise thereto under an atmosphere of nitrogen. After completion of the addition, the mixture was stirred for 2 hours under reflux of tetrahydrofuran and the resulting liquid was transferred to a 300-ml dropping funnel. Next, 30 g of tetrahydrofuran, 0.5 g of cuprous bromide and 22 g (0.204 mole) of ethyl bromide were placed in another 1-liter reactor and cooled to 0° C. Then, the above-described Grignard reagent was added dropwise thereto so that the temperature did not exceed 10° C. After completion of the reaction, 100 g of a saturated aqueous ammonium chloride solution was added and the resulting mixture was allowed to separate into two layers. The organic layer was recovered, freed of tetrahydrofuran under reduced pressure, and distilled to obtain 37.7 g of cis-5-hexadecene (purity 96%, yield 81%, b.p. 149°-152° C./3 mmHg). MS(m/e): 56(100%), 224 (M+, 21%).

Workup

additionAfter completion of the addition
customdid not exceed 10° C
additionwas added
customto separate into two layers
customThe organic layer was recovered
distillationdistilled

Sources & evidence

ORD record: ord-fac0a27091a348d5be65e0c47cf22182
Source dataset: uspto-grants-1998_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05714649

Reaction notes

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