Ammonia → 5-(4'Bromophenyl)-4-pentyn-1-al ethylene acetal

HRID 2106875Notes

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]#[CH:9])=[CH:4][CH:3]=1.[NH2-].[Li+].[Li].N.Br[CH2:15][CH2:16][CH:17]1[O:21][CH2:20][CH2:19][O:18]1.[Cl-].[NH4+]>CS(C)=O>[CH2:20]1[O:21][CH:17]([CH2:16][CH2:15][C:9]#[C:8][C:5]2[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=2)[O:18][CH2:19]1

Participants

Conditions

Temperature: -30 °C

Procedure

4-bromophenylacetylene (10 g, 55 mmol), prepared according to Organic Reactions 5 (1), 50, (1949), in dry dimethyl sulphoxide (7.0 ml) was added to lithium amide (from 66 mmol) of lithium) in liquid ammonia (200 ml). The mixture was stirred for 1 hour at -30° C., 2-(2-bromoethyl)-1,3-dioxolane (10 g, 55 mmol) was added and the mixture was stirred for 2 hours at -30° C. Ammonium chloride (12 g) was added, the ammonia was allowed to evaporate and water (200 ml) was added to the residue. The emulsion was extracted with ether and the organic phase was washed with brine and dried. The solvents were removed and the product purified by dry column chromatography (silica, 5% ether in hexane 1:1 ether:hexane) to give 4.08 g (26% of theory) of 5-(4'bromophenyl)-4-pentyn-1-al ethylene acetal.

Workup

stirringthe mixture was stirred for 2 hours at -30° C
customto evaporate
additionwater (200 ml) was added to the residue
extractionThe emulsion was extracted with ether
washthe organic phase was washed with brine
customdried
customThe solvents were removed
customthe product purified
dry with materialby dry column chromatography (silica, 5% ether in hexane 1:1 ether:hexane)

Sources & evidence

ORD record: ord-6a08d0b158ed48ddb36c542263a1f0f9
Source dataset: uspto-grants-1990_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04931469

Reaction notes

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