1. 1 Dr Nahed Elsayed

2. Learning Objectives Chapter nine introduces carboxylic acids and their derivatives. The chemistry is very similar to that of aldehydes and ketones because of the presence of the carbonyl group. The main topics in this chapter that the students should know and understand include:  The structure of carboxylic acids  The common and IUPAC nomenclature of carboxylic acids  The physical properties of carboxylic acids  The Factors affecting acidity of carboxylic acids.  The different ways to make carboxylic acids  Salt formation reactions of carboxylic acids  The nucleophilic substitution reactions at the carbonyl carbon and the specific products formed in each case.  The chemistry of carboxylic acid derivatives

3. 3 Structure Of Carboxylic Acids  Carboxylic acids are organic acids contain one or more carboxyl group  A carboxyl group is made up of a carbonyl (C=O) group and a hydroxyl (O-H) group  It is often written in condensed form as –CO 2 H or –COOH  Carboxylic acids are classified as aliphatic R-COOH or aromatic Ar-COOH depending on the group bonded to the carboxylic group.  The simplest aliphatic acid is formic acid R= H  The fatty acid is long chain aliphatic acids CH 3 -(CH 2 ) 16 -COOH

4. Nomenclature Of Carboxylic Acids  Some carboxylic acids are called after characteristic properties or their origin. Formula Common name origin of name HCOOH formic acid Latin for ant CH 3 COOH acetic acid Latin for vinegar CH 3 CH 2 COOH propionic acid Greek for milk CH 3 (CH 2 ) 2 COOH butyric acid Latin for butter CH 3 (CH 2 ) 3 COOH valeric acid valerian root Common Nomenclature  The positions of the carbons present on the acid chain, are located by the Greek letters α indicating the carbon atom next to COOH group (C2), β (C3), etc.

5. 5  Some aromatic acids have common names Succinic acid  Example of dicarboxylic acids

6. IUPAC Nomenclature  Find the longest continuous carbon chain contains the COOH group to get the root name of the parent hydrocarbon, then replace the ending -e by the suffix – oic acid.  Number the chain starting with the carbon of COOH group as C-1  If there are substituents identify their names, positions and list them as prefixes in alphabetical order. Examples: (CH 3 ) 2 CH - CH(CH 3 ) - CH 2 - CH 2 - COOH Examples: (CH 3 ) 2 CH - CH(CH 3 ) - CH 2 - CH 2 - COOH is called 4,5-Dimethylhexanoic acid Butanoic acid Pentanoic acid

7. 7  Cyclic compounds containing one or more COOH groups attached to the ring are named by identifying the name of the ring followed by the word carboxylic acid or dicarboxylic acids etc. The carbon atom bearing the carboxylic group is numbered 1 and the substituents are numbered relative to it. 1,4-Butandioic acid 3-Bromo-2-hydroxy-4-hexenoic acid 3-Aminobutanoic acid

8. 8   Some aromatic compounds have common names accepted by the IUPAC also they can be named as benzene carboxylic acids

9. Physical Properties OF Carboxylic Acids Solubility  Carboxylic acids are polar, they can form hydrogen bonds with water molecules   The first four aliphatic acids are completely miscible in water. Higher members are less soluble   Aromatic acids are insoluble in water

10.  Carboxylic acids have exceptionally high boiling points than alcohols and aldehydes, because their dimeric structures. of identical relative molecular masses, For example: M.F. M.Wbp / °C Propanol C 3 H 8 O60.01 97.2 Ethanoic acid C 2 H 4 O 2 60.05 118 Boiling Points Hydrogen-bonded acid dimer

11. compared to alcohols and phenols  Carboxylic acids are stronger acids compared to alcohols and phenols substituents near the carboxyl group the acidity  Electron withdrawing substituents near the carboxyl group increase the acidity  Whereas substituents the acidity.  Whereas electron donating substituents decrease the acidity. 11  HCOOH > CH 3 COOH > CH 3 CH 2 COOH > CH 3 CH 2 CH 2 CH 2 COOH ( size of R group) ( number of e.w.g.)  Cl 3 CCOOH > Cl 2 CHCOOH > ClCH 2 COOH > CH 3 COOH ( number of e.w.g.) Acid Strength

12. 1- Oxidation Of Primary Alcohols 2- Oxidation Of Alkyl Benzenes Preparation Of Carboxylic acids

13. 3- Carbonation Of Grignard Reagents 4- Hydrolysis Of Nitriles or i) KOH ii) H 3 O +

14. Reactions Of Carboxylic Acids 1- Salts Formation

15. 2- Substitution Of Hydroxyl Group General Equation

16. Carboxylic Acid Derivatives Acid Chloride Ester Amide Acid anhydride  The derivatives of carboxylic acids are compounds in which the - OH of carboxylic acid is replaced by nucleopile (-X for acid halide, -OR for ester, -NH 2, -NHR, -NR 2 for amids, -OOCR for anhydride).  Carboxylic acids derivatives can converted to carboxylic acids by simple acidic or basic hydrolysis.

17. Carboxylic Acid Derivatives 1-Nomenclature Of Acid Chlorides  Replace  Replace the -ic acid ending in the name of the parent acid by –yl chloride Ethanoyl chloride Benzoylchloride Propanoyl chloride IUPAC: Ethanoyl chloride Benzoylchloride Propanoyl chloride Acetyl chloride Common : Acetyl chloride

18. 2- Nomenclature of esters  The alkyl group (R’) is written first followed by the name of the parent acid with replacing of the ending –ic acid by –ate : (IUPAC) Ethyl ethanoate Methyl benzoate (common) Ethyl acetate 145 Chem 18 (IUPAC) Methyl propanoate Isopropyl-4-hydroxy-5-methyl-5- hexenoate

19. 3- Nomenclature of amide  Replace the ending oic acid of the parent acid’s by the word amide  If there is R group on the nitrogen atom, it is listed first and designated with –N (IUPAC) Ethanamide Benzamide N-Methylpropanamide (common) Acetamide N-Methylpropionamide (IUPAC) N,N-Dimethylmethamide N-Ethyl-N-methylbenzamide (Common) N,N-Dimethylformamide 145 Chem. 19

20. 4- Nomenclature of anhydride  An anhydride is named by replacing the word acid in the corresponding acid by the word anhydride. Due to it is obtained from corresponding acid by dehydration as shown in the following equation:  (IUPAC) Ethanoic anhydride Benzoic anhydrideButandioic anhydride (Common) Acetic anhydrideSuccinic anhydride 145 Chem20

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22. Reaction of Derivatives of carboxylic acid 145 Chem. 22  On hydrolysis (reaction with H 2 O/ H + ) all carboxylic acid derivatives convert to carboxylic acid.

23. Questions 1- Reaction of with CO 2 under heat and pressure gives: 145 Chem. 23 2- Oxidation of C 6 H 5 CH 2 OH with KMnO 4 gives:

24. 4- The common name of this compound is? A) N,N-Dimethylacetamide B) N,N-Dimethyl propanamide C) N,N-Dimethylpropionamide D) N,N-Dimethylbutanamide 5- Acid halide react with ammonia to give? A) Amines B)Amides C) Phenols D) Alcohols 145 Chem24 3- The most acidic compound is?

25. Questions?