Organic Chemistry Classes with structure

Organic Chemistry Classes “OCC”

When you are preparing for pharmacy examination, organic chemistry is very important to understand many biological interactions and drug binding concepts.

I will enumerate different organic classes with important tips about them. Here we go:

Click to enlarge!

Alkanes

• Also called paraffins, saturated hydrocarbons.
• General formula: R-CH2-CH3.
• Lipid soluble.
• Common reactions: halogenation, combustion.
• Chemically inert to air, heat, light, acids, bases.
• Stable in vivo.

Alkenes

• Also called olefins, unsaturated hydrocarbons.
• General formula: R-CH=CH2. Lipid soluble.
• Common reactions: addition of hydrogen or halogen, hydration (to form glycols), oxidation (to form peroxides).
• Volatile alkenes and peroxides may explode in presence of O2 and spark
• Stable in vivo.
• Hydration, peroxidation, reduction may occur.

Aromatic hydrocarbons

• Based on benzene.
• Exhibit multicenter bonding. Lipid soluble. Common reactions: halogenation, alkylation, nitration, sulfonation. Chemically stable.
• In vivo: hydroxylation, diol formation.

Alkyl halides

• Halogenated hydrocarbons. General formula: R-CH2-X.
• Lipid soluble.
• ↑ degree of halogenation↑ Solubility.
• Common reactions: dehyro-halogenation, nucleophilic substitution.
• Stable on the shelf. Not readily metabolized in vivo.

Alcohols

• Contains OH group.
• May be primary (R-CH2-OH), secondary (R1/R2-CH-OH), or tertiary (R1/R2/R3-C- OH).
• Alcohols are lipid soluble.
• Low molecular weight alcohols are water soluble.
• ↑ hydrocarbon chain length  ↓ water solubility.
• Common reactions: oxidation, esterification.
• Stable on shelf.
• In vivo: oxidation, sulfation, glucuronidation.

Oxidation:

primary alcohol aldehydeacid.

Second aryalcoholketone.

Tertiary alcohol not oxidized.

Phenols

• Aromatic compounds containing OH groups directly connected to aromatic ring.
• Monophenols  one OH.
• Catecholstwo OH.
• Phenol (carbolic acid): water soluble.
• By ↑ ring substitution ↓ water solubility.
• Most phenols are lipid soluble.
• Common reactions: with strong bases to form phenoxide ion, esterification with acids, oxidation to form colored quinones.
• On the shelf: oxidation with air or ferric ions.
• In vivo: sulfation, glucuronidation, aromatic hydroxylation, o-methylation.

Ethers 

• General formula: R-O-R.
• Lipid soluble.
• Partially water soluble.
• By ↑ hydrocarbon chain  ↓ water solubility.
• Common reaction: oxidation to form peroxides (may explode).
• In vivo: o-dealkylation.
• Stability ↑ with size of alkyl group.

Aldehydes

• General formula: R-CHO (contains a carbonyl group C=O).
• Lipid soluble.
• Low molecular weight aldehytes are also water soluble.
• Common reactions: oxidation (to acids, in vivo and in vitro) and acetal formation.

Ketones

• General formula: R-CO-R (contains a carbonyl group C=O).
• Lipid soluble.
• Low molecular weight ketones are also water soluble.
• Non-reactive and very stable on the shelf.
• In vivo: some oxidation or reduction.

Amines

• Contain an amino group (-NH2).
• Primary (R-NH2), secondary (R1/R2-NH), tertiary (R1/R2/R3-N), quaternary (R1/R2/R3/R4-N+ X-).
• Lipid soluble.
• Low molecular weight amines  water solubility.
• By ↑ branching  ↓ water solubility (primary amines and most soluble).
• Quaternary amines (ionic) and amine salts are water soluble.
• Common reactions: oxidation (air oxidation on shelf), salt formation with acids.
• Aromatic amines are ↓ basic↓ reactive with acids.
• In vivo: glucuronidatin, sulfation, methylation.
• 1ry: oxidative deaminatin.
• 1y/2ry:  acetylation.
• 2ry/3ry:  dealkylation.

Carboxylic acids

• General formula: R-COOH (Carboxyl group –COOH).
• Lipid soluble.
• Low molecular weight acid and Na/K salts are water soluble.
• Common reactions: salt formation with bases, esterification, decarboxylation.
• Very stable on shelf.
• In vivo: conjugation (with glucuronic acid, glycine, glutamine), beta oxidation.

Esters

• General formula (R-COOR).
• Lipid soluble.
• Low molecular weight esters are slightly water soluble.
• Common reaction: hydrolysis to form carboxylic acid and alcohol (in vivo by esterases / in vitro).

Amides

• General formula: R-CONH2 or R-CONR1/R2 (lactam form).
• Lipid soluble.
• Low molecular weight amides are slightly water soluble.
• No common reactions.
• Very stable on shelf.
• In vivo: enzymatic hydrolysis by amidases in the liver.