Potassium Hydroxide → Benzene, 1-bromo-4-ethynyl-

HRID 890552Notes

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](Cl)=[CH2:9])=[CH:4][CH:3]=1.[OH-].[K+]>>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]#[CH:9])=[CH:4][CH:3]=1

Participants

Reactant 2

HCID 14797Potassium Hydroxide

HCID 122532331-Bromo-4-(1-chloroethenyl)benzene

Product 1

HCID 136603Benzene, 1-bromo-4-ethynyl-Yield 60%

Procedure

Initially, 4-bromoacetophenone (3) can be treated with powdered phosphorous pentachloride to produce 1-(4-bromophenyl)-1-chloroethylene (4). Compound 4 was then treated with potassium hydroxide to produce 4-bromophenylacetylene (5) at a 60% yield. Treatment of compound 5 with ethyl magnesium bromide was followed by reaction with chlorotrimethylsilane. The resulting product (4-bromophenylethynyl) trimethylsilane (6) was recovered with a 90% yield. Compound 6 was then treated with ethyl magnesium bromide, followed by reaction with carbon dioxide to produce (4-carboxyphenylethynyl) trimethylsilane (7) in 89% yield. Compound 7 was then deprotected using KOH in methanol to form 4-ethynylbenzoic acid (8) in 96% yield. Compound 8 is a useful building block for forming a variety of molecular switches in accordance with the present invention, and was used in forming molecular switches of the following examples.

Sources & evidence

ORD record: ord-e2e2bc65d46b437e93b2f7a46f258ef3
Source dataset: uspto-grants-2006_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06995312B2

Reaction notes

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