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SCH 206
Dr. Solomon DereseDr. Solomon Derese 1
Carboxylic acids, Carboxylic acid derivatives and Nitriles
SCH 206
Dr. Solomon Derese 2
Nomenclature of carboxylic acids and their derivatives and nitriles
Nomenclature of carboxylic acids
The IUPAC names of carboxylic acids are obtained bydropping the final e of the corresponding hydrocarbon andadding –oic acid. Note that the carboxyl carbon atom isalways C-1.Examples
Methanoic acid Ethanoic acid
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H O
O
H CH3 O
O
H
Examples
Formic acid Acetic acid(Ant bite) (Vinegar)
O
O
H
Caproic acid (Aroma of goats)3
Acetum, Latin: vinegarFormica, Latin: ant
Caper, Latin: goat
Most simple carboxylic acids have common namesthat are more widely used than their IUPAC names.
Dirty socks
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O
O
H 4-Hexenoic acid1
23
4
56
Cyclic carboxylic acids are named by using the suffixcarboxylic acid.
ExamplesOO
H
Br
3-Bromocyclohexanecarboxylic acid
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OOH
O
O O
H
OOH
2-Cyclopentenecarboxylic acid
Benzenecarboxylic acid
Benzoyl
m-Benzoylbenzoic acid
(Benzoic acid)
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Compounds with two carbonyl groups are distinguished bythe suffix –dioic acid or dicarboxylic acid asappropriate. The final e in the base name of thecorresponding hydrocarbon is retained.Examples
O
O
H
O
OH Butanedioic acid (Succinic acid)
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O
H
O
O
O
H
1,2-Benzenedicarboxylic acid (Phthalic acid)
O
O
H
O
OH
OH
OH(2R,3R)-2,3-Dihydroxybutanedioic acid
1
2 3
1
23
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Revise the R/S designation of sp3 hybridizedcarbons you learnt in SCH 102.
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I. Acyl chlorides are named by dropping –ic acid from thename of the corresponding carboxylic acid and thenadding –yl chloride
H Cl
O
Cl
OCl
O
Formyl chloride Acetyl chloride Benzoyl chlorideII. Or replacing the carbocylic acid ending with carbocylic
chloride for cyclic acid chlorides.
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Nomenclature of acyl chlorides
Cl
O
Cyclohexanecarbonyl chloride
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Named by dropping the word acid (From the correspondingcarboxylic acid) and replacing it with – anhydride.
Nomenclature of Acid anhydrides Symmetrical anhydrides
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Acetic anhydride Heptanoic anhydride
Mixed anhydrides
Named by giving in alphabetical order, the first part of thenames of the two acids followed by “anhydride”.
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Acetic propanoic anhydride
Benzoic butanoic anhydride
Acetic Propanoic
Butanoic Benzoic
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IUPAC names for esters are derived by first citing the groupderived from the alcohol, followed by the group derivedfrom the carboxylic acid (with the ending –ate or –oate).They are named as alkyl carboxylates - Alkyl from thealcohol, Carboxylate from the carboxylic acid precursor.
Nomenclature of esters
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O
O
Ethyl acetate (Ethyl ethanoate)
Methyl p-chlorobenzoate
1,1-Dimethylethyl E-2-butenoate
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Nomenclature of amidesAmides with an unsubstituted – NH2 group are named byreplacing the – oic acid ending with amide, or by replacingthe – carboxylic acid ending with – carboxamide of thecorresponding carboxylic acid.
Methyl cyclopentanecarboxylate
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If the nitrogen atom is further substituted, the compound isnamed by identifying the substituent and then citing thebase name. Note that the substituents are preceded by theletter N to identify them as being directly attached to N.Examples
O
N
N,N-Dimethyl propanamide
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Simple nitriles are named by adding the suffix – nitrile tothe name of the corresponding hydrocarbon. Note thatthe nitrile carbon is taken as C-1.
Nomenclature of nitriles
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Cyclic nitriles are usually considered as derived fromcarboxylic acids, and are named either by replacing –ic acid/-oic acid with – onitrile.
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Read the attached notes for rules on nomenclatureof polyfunctional organic compounds.
Nomenclature of carboxylic acids and derivatives.Attached separately.
Assignment 18