Carboxylic Acids Unit 6 General Formula - PowerPoint Presentation

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Carboxylic Acids

Unit 6

General Formula

RCOOH and

ArCOOH

Functional Group =OC -OH

Common Names…

1C – Formic Acid (

Methanoic

Acid)From Formaldehyde (methanal)

2C – Acetic Acid (Ethanoic Acid)From Acetaldehyde (

ethanal

)

3C –

Propanoic

Acid (

Propanoic

Acid)

From

Propanaldehyde

(

propanal

)

4C – Butyric Acid (

Butanoic

Acid)

From

Butyraldehyde

(

butanal

)

Uses – Just FUN Facts – Not Tested!

Formic Acid – First Isolated from Ants

Used in dyeing and finishing textiles and many other uses!

Acetic Acid – Naturally produced by usAka vinegar – many usesPropanoic Acid – in Greek, means “first fat”Grain Preservative and antifungal

Butyric Acid – Naturally occurring – Greek for butterSmells like vomit 

Preparation of Carboxylic Acids – You already know this



Oxidation of aldehydes

O KMnO4 O

R-C-H R-C-OH

RCHO

KMnO4

RCO

2

H

Example

Form Pentanoic Acid (S,C,N)

Reactions of Carboxylic Acids

Halogenation: RCO

2

H + X2  RXCO2H + HX

ArCO2H + X2 FeX3

ArXCO

2

H + HX

Form 2,3,4 – trichloroheptanoic acid (str,cond)

O

Cl Cl Cl O

C-C-C-C-C-C-C-OH

+ 3Cl

2  C-C-C-C-C-C-C-OH

+3HCl

CH3(CH2

)5CO2

H + 3Cl

2

CH

3

(CH2)2(CHCl)3CO2H + 3HCl

Examples of Halogenation

Form

paraiodobenzenoic

acid (str) + I2 FeI3 + HI

I

Reactions of Carboxylic Acids

2. Nitration of benzanoic acid

ArCO

2 + HNO3 H2SO4 ArNO2CO

2H + H2OForm metanitrobenzanoic acid (str,cond)

Reactions of Carboxylic Acids

Acid Salt formation can be done 2 ways…

RCO

2H + M° ArNO2CO

2H + H2O

Metal can be same 7 as before

Examples

React

ethanoic

acid with sodium (str,name,cond) O O

2C-C-OH + 2Na2(C-C-O-)Na

+

+ H

2

2CH

3

CO

2

H+2Na2(CH

3CO2

-)Na+ +H

2 Sodium

ethanoate

Examples

To name acid salts:

Name Metal ion

Drop –ic acid and add –ateEx: React butyric acid with magnesium (str,cond,name)

Acid Salt Formation – 2nd Way!

2. Carboxylic acid + metal hydroxide

 acid salt + water

RCO2H + MOH(RCO

2-)M+

+ H

2

O

React

butanoic

acid with magnesium hydroxide (

str,cond

, name prod)

Example

React

propanoic

acid with aluminum hydroxide (str, cond, name product)

Other Reactions of Carboxylic Acids

Convert carboxylic acids to “functional derivatives”

Functional Derivative – an organic compound containing the acyl group O

Acyl group = RCO = R-C-

Conversion to acid chlorides

O O

4. R-C-OH + SOCl

2 R-C-Cl + SO2 + HCl

RCO2H + SOCl2  RCOCl + SO

2

+ HCl

Carboxylic acid + thionyl chloride

acid chloride + sulfur dioxide + hydrogen chloride

Examples

React

hexanoixc

acid with thionyl chloride (s,c,np) O O

C-C-C-C-C-C-OH + SOCl2C-C-C-C-C-C-Cl + SO2

+HCl

CH

3

(CH

2

)

4

CO2H + SOCl2

 CH3(CH2)4

COCl + SO2+HCl

To name acid chlorides:Drop –

ic acidAdd –yl

chloride

Conversion to amides

5.

Converting carbox. Acids to amides

O H O HR-C-OH + H-N-H  R-C-N-H + H2O

Carboxylic acid + ammonia  amide + water

Example

Rct

pentanoic acid w/ammonia (s,c,np) O H O HC-C-C-C-C-OH + H-N-H  C-C-C-C-C-N-H + H

2OCH

3

(CH

2

)

3

COH + NH

3

 CH

3(CH2

)3CONH2

+ H2O

To Name Amides: pentanimide

Drop –e from corresponding alkane

Add –amide

Conversions to Esters

Fischer

Esterification

O OR-C-OH + R’-OH H2SO4 R-C-O-R’ + H2O

RCO2H + R’OH H2SO4 RCO

2

R’ + H

2

O

Carboxylic acid +

alcohol

ester

+ water

Example

React

propanoic

acid with butanol (s,c,np) O O

C-C-C-OH + C-C-C-C-OH H2SO4 C-C-C-O-C-C-C-C + H2O

CH

3

CH

2

CO

2

H + CH

3(CH2)2

CH2OH H2SO4 CH

3CH2CO2(CH2

)3CH3+ H2

O butyl propanoate

Naming Esters

To Name Esters:

Name R’ side as chain (from alcohol)

Drop – ic acid add – ateEX: form Propyl Butanoate (s,c,nr)