AROMATIC HYDROCARBONS Flashcards
Benzene is usually used as?
industrial solvent
Benzene chemical formula
C6H6
Benzene was first isolated in ____ by English chemist _______ from the oily residues after heating while oil under pressure to produce a gas used to illuminate buildings in London.
Michael Faraday, 1825
Benzene, aside from being an industrial solvent, is also used as?
gasoline additive
C6H5CO2H
benzoic acid
A compound obtained by chemical degradation of gum benzoin, the fragrant balsam exuded by a tree that grows on the island of Java, Indonesia.
Benzoic acid (C6H5COE2H)
The fragrant balsam exuded by a tree that grows on the island of Java, Indonesia.
Gum benzoin
Thus benzene, toluene, and related hydrocarbons, while not particularly pleasant- smelling themselves, were classified as aromatic because they were obtained from _______ substances.
fragrant
benzoic acid is fungiSTATIC (as preservative)
inhibits growth of fungi
This Austrian chemist, recognized in ______ that most aromatic substances have formulas that can be derived from benzene by replacing one or more hydrogens by other atoms or groups.
Joseph Loschmidt, 1861
Replacing one of the hydrogens with a different functional group.
Benzene Derivatives
The parent hydrocarbon of the especially stable compounds known as aromatic compounds.
Benzene
The term _______ thus came to mean any compound structurally derived from benzene.
aromatic
These aromatic compounds are hydrocarbons that contain a ____________ as a structural unit.
benzene ring
In addition to benzene, other examples include _____ and ________.
toluene and naphthalene
Breaks and releases benzene from benzoic acid.
Calcium Oxide (CaO)
All arenes are either ________ at room temperature; none are gases.
liquids or solids
Aromatic hydrocarbons are ______ in water.
insoluble
Benzene was once widely used as a solvent, but evidence of its __________ properties prompted its replacement by less hazardous solvents.
carcinogenic
These have the potential to cause cancer.
Carcinogenic
The most common reactions of aromatic compounds involve substitution of other atoms or groups for a ring hydrogen on the aromatic unit.
electrophilic aromatic substitution reaction
The most common reactions of aromatic compounds involve ________ of other atoms or groups for a ring hydrogen on the aromatic unit, or more precisely called an electrophilic aromatic substitution reaction.
substitution
Ideal temperature to takes place reaction in electrophilic aromatic substitution reaction.
0 - 50°C
The bromination or chlorination of benzene requires a Lewis acid such as ?
ferric bromide or ferric chloride
(ferric chloride is most used)
Electrophilic iodine (I+) is obtained by treating I2 with an oxidizing agent such as ?
nitric acid
Nitration of benzene with nitric acid requires _______ as a catalyst.
sulfuric acid
Purpose of sulfuric acid in nitration?
Protonates nitric acid
Fuming sulfuric acid (a solution of SO3 in sulfuric acid) or concentrated sulfuric acid is used to sulfonate ?
aromatic rings
A sulfonic acid is a (strong acid / weak acid) because of the three electron- withdrawing oxygen atoms and the stability of its conjugate base.
strong acid
triangle meaning in a chemical reaction
heat
what group is SO3H
sulfonyl group
Two electrophilic substitution reactions bear the names of chemists Charles Friedel and James Crafts.
Friedel-Crafts acylation - places an acyl group on a benzene ring
Friedel-Crafts alkylation - places an alkyl group on a benzene ring.
Either an _______ or an _________ can be used for Friedel-Crafts acylation.
acyl halide
acid anhydride
In Friedel-Crafts Acylation, acylation can only be used to give _____ because acyl halide decomposes into CO and HCL.
Ketones
In Friedel-Crafts Acylation, arylamines form complexes with lewis acid (AlCl3) so aryl amines are unreactive.
In Friedel-Crafts Acylation, amines & Alcohol can give competing nitrogen or oxygen acylation rather than the required ring acylation.
The Friedel-Crafts alkylation reaction substitutes an _________ for a hydrogen.
alkyl group
Alkyl fluorides, alkyl chlorides, alkyl bromides, and alkyl rosdudes can all be used.
Friedel-Crafts Alkylation
Aside from aluminum chloride (AlCl3), _____________ can be used.
ferric chloride (FeCl3)
zirconium chloride (ZrCl4)
In Friedel-Crafts Alkylation, vinyl/arylhalides are _______ because intermediate carbocations are said to be unstable.
unreactive
In Friedel-Crafts Alkylation, alkylation reaction are prone for _________.
carbocation rearrangements
In Friedel-Crafts Alkylation, lewis acid catalyst form complex on arylamines (unreactive).
olol suffix meaning
Beta-blockers , for anti-hypertension
Phenobarbital use
anticonvulsant / antiseizure
Phenytoin use
anticonvulsant / antiseizure
Phenylbutazone use
NSAID , Non-selective COX Inhibitor
(cyclooxygenase is involved in inflammation)
(non selective means it inhibits both COX-1 & COZ-2)
Atorvastatin use
HMG-CoA reductase inhibitor , for antihyperlipidemic agent
(hydroxymethyl glutaryl)
17a-Ethinylestradiol use
synthetic steroid , prepared from ESTRONE
for birth control pills
(not naturally occuring, synthesized in the laboratory)
Warfarin use
anti-coagulant (prevent blood clot)
Amphetamine use
psychostimulant
for treatment of ADHD (attention deficit hyper activity disorder), narcolepsy (chronic neurological disorder, thalamus is affected)
to manage obesity
