Amines - Derivatives of Ammonia

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1 Amines - Derivatives of Ammonia lassification by the number of attached groups ethylamine diethylamine triethylamine

2 Amines - Derivatives of Ammonia lassification by the type of attached groups 2 2 aromatic amines aliphatic amines

3 Amines - omenclature Amines containing simple groups are named with common nomenclature. Simple groups include: Unbranched alkyl groups: methyl, ethyl, propyl, butyl,., decyl Branched 3- and 4-carbon alkyl groups: isopropyl, isobutyl, s-butyl, t-butyl Unsubstituted cycloalkyl groups: cyclohexyl and cyclopentyl ethylmethylamine 3 3 2º 1º isopropylamine 3 cyclohexylmethylamine 3 3 2º 3º 23 ethyldimethylamine

4 Amines - omenclature aniline p-methylaniline 4-methylaniline -methylaniline

5 Amines - omenclature amino butanoic acid (dimethylamino)-1-butanol ,-dimethyl-2-pentanamine

6 Amines - eterocyclic itrogen ompounds

7 Amines - Physical Properties 1º amine 2º amine 3º amine 1) Both 1º and 2º amines exhibit strong secondary forces (hydrogen bonding), primary amines slightly more so than secondary amines. 2) ydrogen bonding involving nitrogen atoms is weaker than that involving oxygen atoms because nitrogen is less electronegative than oxygen. a) The secondary forces in primary and secondary amines are weaker than those in alcohols. b) The strength of - hydrogen bonding in amines is comparable to the dipole-dipole forces in aldehydes and ketones.

8 Amines - Physical Properties 1º amine 2º amine 3º amine 1) Tertiary amines do not possess an - bond and therefore exhibit only weak secondary forces. 2) The strength of the weaker secondary forces in tertiary amines is comparable to those in ethers and hydrocarbons. 3) Tertiary amines have melting and boiling points considerably lower than those of primary and secondary amines, comparable to those of ethers and hydrocarbons.

9 Amines - Physical Properties

10 Amines - Physical Properties

11 Amines - Basic ompounds When dissolved in water, amines generate hydroxide ions =, alkyl, aryl The product of the reaction is a salt and it is named from the name of the starting amine. 3 methylamine a solution of methylammonium hydroxide

12 Acidities and Basicities of rganic ompounds Values for 0.10 M aqueous solution ompound Structure [ - ] [3 + ] p Ionization (%) sodium hydroxide a 1.0 x x methyl amine x x aniline x x water x x ethanol x x phenol x x acetic acid x x benzoic acid x x hydrochloric acid l 1.0 x x

13 Amines - Basic ompounds Ammonia may be reacted with a strong acid to quantitatively yield an amonium salt. 3 + l 4l ammonia hydrogen ammonium chloride chloride An amine may be reacted with a strong acid to quantitatively yield an amine salt. 3 methylamine + l 3 l- + methylammonium chloride

14 Amines - Properties of Amine Salts 3 methylamine + l 3 + l- methylammonium chloride mp -94º, bp -6º mp 232º The melting and boiling points of amine salts are much higher than those of the corresponding amines. All amine salts are solids at room temperature. Amine salts are much more soluble in water than amines due to the strong interaction of water molecules with ions. Amines are soluble in neutral or lower p where they are converted into their salt forms.

15 Amines - Amine Based Drugs 2 l l- phenylephrine hydrochloride ESYEPIE l l procaine hydrochloride VAAIE diphenhydramine hydrochloride BEADYL

16 Biologically Interesting Amines

17 Biologically Interesting Amines

18 Interconversion of Amine Forms l Base l- + ocaine (Free Base) ocaine hydrochloride

19 Amides - Structure and lassification Subclassification º 2º 3º an amides engage in hydrogen bonding??

20 Amides - Structure and lassification The amide is better represented as a dipolar ion: Because the bond between the carbonyl carbon atom and the nitrogen atom has a partial double bond character, the bond angles about the carbonyl carbon atom and nitrogen atom are both close to 120 (sp 2 hybridization). The dipolar ion nature of the amide bond is very important in determining the structure and function of protein molecules.

21 Amides - Synthesis At low temperatures a carboxylic acid and an amine will take part in a simple acid-base reaction to form an ammonium salt o carboxylic amine ammonium acid carboxylate

22 Amides - Synthesis At a higher temperature, a condensation reaction takes place between the carboxylic acid and the amine. 1 + >100 o carboxylic ammonia primary acid amide >100 o carboxylic 1º amine secondary acid amide >100 o carboxylic 2º amine tertiary acid amide

23 Amides - omenclature ,2-dimethyl propanamide 223 -propyl benzamide

24 Amides - Synthesis and omenclature >100 o acetic acid methylamine -methylacetamide aniline acetic -phenyl acetic anhydride acetamide acid

25 Amides - ondensation Polymers adipic acid hexamethylene diamine 2222 mix at room temperature hexamethylene diammonium adipate heat 2 ( ) n polyhexamethylenediamine adipate ylon 6,6

26 Amides - Physical Properties Amides have the strongest secondary attractive forces and the highest melting and boiling points of any covalent organic compounds. Potential ydrogen Bonds:

27 Amides - Physical Properties 3 acetic acid 3 3 -methylacetamide 3 acetamide 3 3 3,-dimethylacetamide

28 Amides - Physical Properties The resonance structure of the amide functional group results in a large charge separation in an amide molecule resulting in large polarity and secondary attractive forces.

29 Amides - omparison to ther Families

30 Amides - Basic ydrolysis 2, a a + 2 a?? [ ]

31 Amides - Basic ydrolysis Example a + - 2,-diethylbenzamide a sodium benzoate diethylamine

32 Amides - Acid ydrolysis 2, ?? [ ]

33 Amides - Acid ydrolysis Example S4 2,-diethylbenzamide S benzoic acid diethylammonium hydrogen sulfate

All Classes of Organic Compounds

Amines All Classes of Organic Compounds ydrocarbons Functionalized ydrocarbons F,Cl,Br O,S, Alkanes Alkenes Alkynes Aromatics alides -O- -S- -- Alcohols Phenols Ethers Thiols Dissulfides Amines O C O C