Foundations of Medicinal Chemistry - Video Notes

Question-and-answer flashcards covering key concepts from the lecture notes on foundations of medicinal chemistry and functional groups.

What defines an ionic bond?

An attractive force between oppositely charged ions formed by the transfer of electrons; ions form because atoms can achieve the electronic configuration of a noble gas.

How do ions form in ionic bonding?

Through the transfer of electrons so that atoms achieve a noble gas electronic configuration.

How are covalent bonds formed?

They form when atoms with similar electronegativities share electrons; molecules are composed predominantly of covalent bonds.

What is a dipolar (coordinate) covalent bond?

A covalent bond in which one atom donates both electrons to the bond.

What does hydrophilic mean in drug solubility terms?

Water-loving; substances that readily bond to water or dissolve in aqueous solvents.

What does lipophilic mean?

Lipid-loving; substances that readily dissolve in lipids; often poorly soluble in water.

What is van der Waals force?

A weak attraction between nonpolar molecules due to induced dipoles; contributes to lipid solubility.

What is dipole-dipole bonding and its significance?

A stronger intermolecular force between polar molecules; hydrogen bonding is a special case and increases water solubility of organics.

What is ion-dipole bonding?

Bonding between an ion and a dipole (as in water).

What is the general formula for alkanes?

CnH2n+2.

What suffix is used for alkane names?

-ane.

What is the formula for cycloalkanes?

CnH2n.

Give examples of simple alkanes mentioned and their formulas.

Methane (CH4) and Ethane (C2H6).

Provide examples of alkynes and alkenes with their formulas as listed.

Alkynes: Acetylene (C2H2), Propyne (C3H4), Butyne (C4H6). Alkenes: Ethene (C2H4), Propene (C3H6), Butene (C4H8).

What are the physical-chemical properties of alkanes?

Van der Waals attractions; insoluble in water; low boiling point; generally stable.

What is the solubility trend for alkanes in water and lipids?

Non-soluble in water; lipophilic (lipid-loving).

What is the general structure for alcohols as shown in notes?

R-C-OH (hydroxyl group attached to carbon).

What is the IUPAC name for isopropyl alcohol?

2-Propanol.

What is the IUPAC name for tert-butyl alcohol?

2-Methyl-2-propanol.

How are alcohols oxidized by oxidizing agents?

Primary alcohols oxidize to aldehydes (and can further oxidize to carboxylic acids); secondary alcohols oxidize to ketones; tertiary alcohols are resistant.

What is the common name and IUPAC name for phenol?

Common name: phenol (carbolic acid); IUPAC name: phenol.

Why are phenols acidic?

The OH proton can be donated; the resulting phenoxide anion is stabilized by resonance.

What are the physical-chemical properties of ethers?

Low boiling point; van der Waals forces; smaller ethers are slightly soluble in water; solubility decreases with larger hydrocarbon portion; structure R-O-R'.

What hazard can ethers form upon storage?

Peroxides.

What are thioethers?

R-S-R'; generally lipophilic; nomenclature similar to ethers (e.g., diethyl thioether).

What is the IUPAC name for acetone?

Propan-2-one (2-propanone).

Name some aldehydes listed with common and IUPAC names.

Formaldehyde (methanal), Acetaldehyde (ethanal), Propionaldehyde (propanal).

What are the solubility and reactivity traits of aldehydes and ketones?

Water soluble to some extent; ketones are relatively nonreactive; aldehydes are rapidly oxidized to carboxylic acids.

What is a primary amine? Give an example from notes.

A primary amine has one carbon substituent on nitrogen (R-NH2); example: isopropylamine (2-aminopropane).

What is a secondary amine?

Amines with two carbon substituents on nitrogen (R-NH-R').

What is a tertiary amine?

Amines with three carbon substituents on nitrogen (R-NR'-R'').

How do amines aid drug solubility?

They can form hydrogen bonds with water and, when protonated, ion-dipole interactions; primary amines are generally more water-soluble.

What is the Brønsted definition of a base?

A substance that accepts a proton from an acid.

What are ammonium salts used for in drugs?

Salt formation increases water solubility and dissolution when dissolution is poor or stability is an issue.

What are quaternary ammonium salts?

Nitrogen bound to four carbons; cannot be regenerated to the original amines; cannot cross the blood-brain barrier; very stable and water soluble.

What is a carboxylic acid?

A compound with a carbonyl and a hydroxyl group; forms salts with bases; salts dissolve in water; strong hydrogen bonding.

What is the general reaction of carboxylic acids with bases?

Formation of carboxylate salts which can dissociate and become water soluble.

What are esters?

Formed by reaction of an alcohol with a carboxylic acid; reduced hydrogen bonding; easily hydrolyzed in base, water, or acid.

What is lactone?

A cyclic ester; can be five- to fourteen-membered rings; behaves similarly to esters.

What are amides?

Formed from a carboxylic acid and an amine; good water solubility; more stable in vivo than esters; used for drugs with prolonged activity.

What is a lactam?

A cyclic amide; the best-known are the β-lactams.

What are carbonate, carbamate, and urea derivatives generally like?

Carbonates and carbamates are unstable to acid/base conditions; ureas are relatively nonreactive solids.

What are sulfonic acids?

Strong acids that are water soluble; examples include benzene sulfonic acid, methanesulfonic acid, p-toluenesulfonic acid.

What are sulfonamides?

Drugs with a benzene sulfonamide nucleus; aryl sulfonamides are weak acids; the SO2 moiety stabilizes the nitrogen anion by resonance.

What is a nitro group?

A neutral functional group represented as NO2; common in drug molecules (e.g., metronidazole, nitrazepam).

What is an oxime?

A functional group formed from the reaction of an aldehyde or ketone with hydroxylamine; found in cephalosporin antibiotics; generally neutral.