alcohol, ethers and amines

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Alcohol, ethers andamines

-Properties- Preparation- Uses- PCK

TOPIC6:



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ALCOHOL



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Alcohol: Properties•

hydroxyl group makes the alcohol molecule polar.forms hydrogen bonds to one another and to other compounds.

• Methanol, ethanol, and propanol

miscible in water

hydroxyl group wins out over the short carbonchain.

• Butanol moderately solublethere’s a balance between the

twotrends.

• Alcohols of five or more carbons (Pentanol andhigher)

effectively insoluble in water because of thehydrocarbon chain's dominance.



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hydrogen bonding alcohols tend tohave higher boiling points than

comparable hydrocarbons and ethers. Can show either acidic or basic

properties at the O-H group.

Alcohols can also undergo oxidation: aldehydes, ketones,

carboxylic acids.

dehydration: alkenes. nucleophilic substitution reactions:

after enzymatic activation. (the lonepairs of electrons on the oxygen of the hydroxyl group also makes

http://var/www/apps/conversion/wiki/Saccharomyces_cerevisiae



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1. Fermentation

Ethanol for use in alcoholic beverages, andthe vast majority of ethanol for use as fuel, isproduced by fermentation. When certain

species of yeast, most importantly,Saccharomyces cerevisiae, metabolize sugar in the absence of oxygen, they produceethanol and carbon dioxide. The chemical

equation below summarizes the conversion:

C6H12O6 2CH3 CH2 OH+ 2CO2

Zymase

PREPARA TION OF ALCOHOL



http://var/www/apps/conversion/wiki/Alcoholic_beverage






http://var/www/apps/conversion/wiki/Metabolism

http://var/www/apps/conversion/wiki/Polysaccharide

http://var/www/apps/conversion/wiki/Oxygen

http://var/www/apps/conversion/wiki/Carbon_dioxide


http://var/www/apps/conversion/wiki/Carbon_dioxide

http://var/www/apps/conversion/wiki/Oxygen

http://var/www/apps/conversion/wiki/Polysaccharide

http://var/www/apps/conversion/wiki/Metabolism




http://var/www/apps/conversion/wiki/Yeast

http://var/www/apps/conversion/wiki/Alcoholic_beverage



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Industrial Preparation of Ethanol

• Ethene and steam are passed over phosphoric acidcatalyst at 330C under high pressure of 6 Mpa to produceethanol.

CH2 = CH2 + H2OCH3CH2OH

H3PO4

acid



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2. Hydration of alkenes

3. Reduction from

H+

CH3

CH3CH2

C

CH3

CH3

CH3 OHCHOH

electrophilic addtion:

Markovnikov rule

RCHO

NaBH4

RCH2OH

( or LiAlH4 )

( or LiAlH4 )

NaBH4RCOR' RCH(OH)R'

(1) Aldehyde

(2) ketone

LiAlH 4

CR CR

O

OH H2OH

H+(3) Carboxylic acid

(CH3CH2 ) O2LiAlH4 /

H 2 O

O

H

H+ ,

O H

(19-11)



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Alcohol: Uses

Isopropyl alcohol solvent for paintsand chemical processes.

used as a beverage (ethanol only),as fuel and for many scientific,medical, and industrial utilities.

ethanol and methanol, can be usedas an Alcohol fuel ethanol can be used as a solvent in

medical drugs, perfumes, andve etable essences such as vanilla



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• Ethanol antiseptic to disinfect theskin before injections are given, often

along with iodine.• Ethanol-based soaps are becoming

common in restaurants and areconvenient because they do notrequire drying due to the volatility of the compound.

• Alcohol preservative for

specimens.• Glycerol possesses good

moisturizing properties, so about

50% of the amount produced goes



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ETHERS



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The general structure foran ether

Ether is a class of organic compounds

which contain an ether group — an oxygenatom connected to two (substituted) alkylor aryl groups — of general formula R–O–R'.



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Ethers: Properties

• Simple ethers are volatile, flammableliquids.

• Slightly soluble (low MW) in water

• Dipolar, so…

- tend to be higher boiling thanhydrocarbons of the same mass.

- good at dissolving many organiccompounds.

• Low reactivity towards many reagentsmakes them good solvents for chemical

reactions.



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• Cyclic ethers such as tetrahydrofuranand 1,4-dioxane are totally miscible

in water because of the moreexposed oxygen atom for hydrogenbonding as compared to aliphaticethers.



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The Williamson Synthesis of Ethers

- prepare unsymmetrical ethers where the alkyl groupsare not the same.- The reaction involves an SN2 reaction in which analkoxide ion replaces a halogen,sulfonyl, or sulfate

group. Usually, alkyl halides are used.- The alkoxide can be prepared by the reaction of thecorresponding alcohol with an active metal such asmetallic Sodium or the use of a metal hydride like NaH

acting upon the alcohol. The resulting alkoxide salt isthen reacted with the alkyl halide (sulfonate or sulfate)to produce the ether in an SN2 reaction. See Fig 3 below)



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MECHANISM FOR ALCOHOLCONDENSATION TO GIVE AN ETHER

Step 1: n acid/base reaction. Proton donation of

the alcoholic oxygen to make a better leaving group. This step is very fast andreversible. The lone pairs on the oxygenmake it a Lewis base.

Step 2: The O of the second alcohol moleculefunctions as the nucleophile and attacks todisplace the good leaving group, a neutralwater molecule, by cleaving the C-O bond.This creates an oxonium ion intermediate.

Step 3: nother acid / base reaction. The proton is

removed by a suitable base (here a water molecule, ROH is another alternative) togive the ether product.



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Ethers: Uses

• Diethyl ether

is a common laboratory solvent.

has a high cetane number of 85 - 96and is used as a starting fluid for dieseland gasoline engines because of its

high volatility and low autoignitiontemperature.



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Anesthetic use

• Modern anesthetic agents, such as methylpropyl ether (Neothyl) andmethoxyflurane (Penthrane) reduce side

effects such as postanesthetic nausea andvomiting.



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Recreational use

• Ether, mixed with ethanol, was marketedin the 19th century as a cure-all andrecreational drug, during one of Western

society's temperance movements.• At the time, it was considered improper for

women to consume alcoholic beverages atsocial functions, and sometimes ether-containing drugs would be consumedinstead

• Due to its immiscibility with water and thefact that non-polar organic compounds arehighly soluble in it, ether is also used in

the production of freebase cocaine.



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Amines

e genera s ruc ure o



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e genera s ruc ure oan amine

Amines are organic compounds andfunctional groups that contain a

basic nitrogen atom with a lone pair.Amines are derivatives of ammonia,wherein one or more hydrogenatoms are replaced by organicsubstituents such as alkyl and aryl



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Amines: Properties

• The boiling point of amines is higher thanthose of the corresponding phosphines,but generally lower than those of the

corresponding alcohols.• Methyl-, dimethyl-, trimethyl-, and

ethylamine are gases under standardconditions, whereas diethylamine and

triethylamine are liquids. Most othercommon alkyl amines are liquids; high-molecular-weight amines are, of course,solids.



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•

Gaseous amines possess a characteristicammonia smell, liquid amines have adistinctive "fishy" smell.

• Most aliphatic amines display some solubilityin water, reflecting their ability to form

hydrogen bonds. Solubility decreases with theincrease in the number of carbon atoms,especially when the carbon atom number isgreater than 6.

• Aliphatic amines display significant solubilityin organic solvents, especially polar organicsolvents. Primary amines react with ketonessuch as acetone, and most amines areincompatible with chloroform and carbontetrachloride.



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Preparation of Amine

LiAlH 4

O

NH CH3 NH CH3

HH

CH3 N H2Br CH3

( )CH3 N2 HBr CH3 Br CH3

( )CH3N

4Br ( )CH3

N3

R NCLiAlH4

R H N2C H2R X + R NC + XCN

(1) Alkylation from ammonia or other amines

(2) From alkyl halide:

(3) Reduction from amides:



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1. Hofmann's method

This reaction takes place in a sealed tube at a temperature of about

100 C and a mixture of primary, secondary and tertiary amines is

obtained.

CH3I + NH3 CH3NH2 + HI

CH3NH2 + CH3I ( CH3)2NH+ HI

(CH3)2NH+ CH3I ( CH3)3N+ HI(CH3)3N + CH3I (CH3)4NI-

If excess of alcoholic ammonia is used in the reaction, primary amine is the

main product and if alkyl halide is used in excess, tertiary amine is the main

product.

2. From alcohol

A mixture of primary, secondary and tertiary amines is obtained when a

mixture of alcohol vapour and ammonia is passed over heated Alumunia



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Amines: Uses

Dyes

• Primary aromatic amines are used as astarting material for the manufacture of azo

dyes. It reacts with nitric(III) acid to formdiazonium salt, which can undergo couplingreaction to form azo compound. As azo-compounds are highly coloured, they arewidely used in dyeing industries, such as:

• Methyl orange• Direct brown 138

• Sunset yellow FCF

• Ponceau

http://en.wikipedia.org/wiki/Methyl_orange

http://en.wikipedia.org/w/index.php?title=Direct_brown_138&action=edit&redlink=1

http://en.wikipedia.org/wiki/Sunset_yellow

http://en.wikipedia.org/wiki/Ponceau


http://en.wikipedia.org/wiki/Sunset_yellow

http://en.wikipedia.org/w/index.php?title=Direct_brown_138&action=edit&redlink=1

http://en.wikipedia.org/wiki/Methyl_orange



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Drugs

• Chlorpheniramine antihistamine

that helps to relieve allergic disordersdue to cold, hay fever, itchy skin,insect bites and stings.

• Chlorpromazine tranquillizer thatsedates without inducing sleep. It isused to relieve anxiety, excitement,

restlessness or even mental disorder.

















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EXAMPLES






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Product Name : Heineken (alcoholicbeverages)

Name of Chemicals : EthanolChemical Type : Alcohol









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Product Name : Spray duster (aerosolpropellants)

Name of Chemicals : Dimethyl Ether (DME)Chemical Type : Ethers









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Product Name : Hayleve (drugs)

Name of Chemicals : Chlorphenamine

maleate(CPM; Chlor- Trimeton, Piriton, Chlor-

Tripolon)

Chemical Type : Amine











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THANK YOU…





alcohol, ethers and amines

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