Amines and Related Nitrogen-containing Functional Groups

Flashcards for reviewing lecture notes on Amines and related Nitrogen-containing Functional Groups

AMINES

Basic nitrogen compounds with single bonds.

Amine

Nitrogen compound where nitrogen is bonded to three other atoms, may be primary, secondary, tertiary, or quaternary.

Primary Amine

An amine with one carbon group bonded to the nitrogen atom.

Secondary Amine

An amine with two carbon groups bonded to the nitrogen atom.

Tertiary Amine

An amine with three carbon groups bonded to the nitrogen atom.

Quaternary Amine

An amine with four carbon groups bonded to the nitrogen atom.

Amino Group

A polar and basic group, -NH2

Amine Nomenclature

Indicate the hydrocarbon moiety first, then add the amine ending.

Methylamine

CH3-NH2

Aniline

C6H5-NH2

Properties of Amines

Amines are synthetic intermediates but they are rather toxic chemicals and their important reactions are Alkylation, Acylation, Salt formation and Imine formation.

Acylation of Amines

Reaction with acyl chlorides to give amides.

Imine Formation

Reaction with aldehydes or ketones.

Oximes

R-CH=N-OH, important nitrogen containing functional group

Nitrates

R-O-NO2, important nitrogen containing functional group

Nitrites

R-O-NO, important nitrogen containing functional group

Hydroxamic Acids

R-CO-NH-OH, Very toxic, N-hydroxiyamides or acyl/aroyl hydroxylamines

Hydrazine

H2N-NH2, can be alkylated and acylated

Hydrazides

NH-NH-CO-CH3 acetic acid hydrazide, important antimicrobial agents in medicinal chemistry

Imines

-C=N- is imino group, N-nonsubstituted imine, N-substituted imine. Stability order: N-aromatic substituted > N-aliphatic substituted > N-nonsubstituted imines, N-aromatic substituted imines are called «Schiff Bases»

Hydrazones

Products of hydrazines with aldehydes and ketones. These compounds have generally antimicrobial property.

Nitrile (Cyanide)

-CN cyano moiety, Toxic moiety

Azo Compounds

compound where R-N=N-R

Azoxy Compounds

compound where R-N=N-R1

N-NITROSAMINES

compound where C6H5-NH-NO

Nitro Compounds

compound where R-NO2

Nitroso Compounds

compound where R-NO

Nitric Acid Esters (Nitrates)

compound where R-O-NO2

Nitrous Acid Esters (Nitrites)

compound where R-O-NO

Nitrones

N-oxide of imines.

Urea and Derivatives

HO-CO-OH carbonic acid, NH2-CO-OH carbamic acid, NH2-CO-NH2 carbamide (urea), monoamide of carbamic acid and a diamide of carbonic acid. Different nitrogenes can be named either N, N’ or N1, N3. Substituted with alkyl, aryl or other functional groups.

Ureides (N-acylurea)

NH2-CO-NH-CO-R, Cyclic ureide is also important in pharmaceutical chemistry: Malonylurea (BARBITURIC ACID)

Carbamates (Uretane)

NH2-CO-OR, Carbamic acid esters are called as carbamates or uretanes

SEMICARBAZIDE (N-aminourea)

NH2-CO-NH-NH2

SEMICARBAZONE (N-aminourea)

NH2-CO-NH-NH=CH(R)-R

THIOSEMICARBAZIDES (N-aminourea)

NH2-CS-NH-NH2

THIOSEMICARBAZONES (N-aminourea)

NH2-CS-NH-NH=CH(R)-R

THIOALCOHOLS

R-SH, important sulphur containing functional group

THIOPHENOLS

C6H5-SH, important sulphur containing functional group

THIOETHERS (SULFIDES)

R-S-R, important sulphur containing functional group

SULFOXIDES

R-SO-R, important sulphur containing functional group

SULFONES

R-SO2-R, important sulphur containing functional group

SULFONIC ACIDS

R-SO3H, important sulphur containing functional group

SULFONAMIDES

R-SO2-NH2, Arylsulfonamides are important antimicrobial agents

SULFONYL CHLORIDE

R-SO2-Cl, Important SIM for producing sulfonamides

SULFONYLUREA

R-SO2-NH-CO-NH2, are important antihyperglycemic compounds

THIONES

ring ketones with S (with the replacement of O in ketones)

POLIFUNCTIONAL GROUPS

May contain more than one functional group in a molecule. Priority: carboxylic acid > carboxylicacid derivatives > aldehydes and ketones > alcohol > amine > double bond.

2-propenoic acid (acrylic acid)

CH2=CH-COOH

2-butenoic acid (crotonic acid)

CH3-CH=CH-COOH

acrolein

CH2=CH-CHO

crotonic acid

CH3-CH=CH-COOH

lactic acid

CH3-CH(OH)-COOH

glycine

NH2-CH2-COOH

alpha-alanine

CH3-CH(NH2)-COOH

beta-alanine

H2N-CH2-CH2-COOH

Ethylenglycol (GLYCOL) or 1,2-ethanediol

CH2OH CH2OH

Glycerol (GLYCERIN) or 1,2,3-propanetriol

CH2OH CHOH CH2OH

oxalic acid

COOH COOH

malonic acid

COOH CH2 COOH

succinic acid

COOH CH2 CH2 COOH

IMPORTANT REACTIONS IN MEDICINAL CHEMISTRY

Alkylation (amines), Acylation (amines), Halogenation (aromatic substitution), Esterification (carboxylic acid, alcohol), Sulphonation (aromatic substitution), Nitration (aromatic substitution), Schiff base formation (imines, amines, aldehydes, ketones), Oxidation (Aldehyde, ketone, alcohol, amine), Reduction (aldehyde, ketone, nitro, azo,double bond), Hydrolysis (ester, amide, imine), Decarboxylation (carboxylic acid), Dealkylation (pr and sec amine, ether, thioether)

1st group substituents

OH, NH2, X and CH3 Reactions are easier compared to 2nd group substituents, ortho and para directing

2st group substituents

COOH, and NO2 groups Reactions are more difficult compared to 1st group substituents, meta directing