Synthesis of drugs Flashcards
Is the hydrolysis of aspirin an addition or a substitution reaction?
Substitution
Acid chloride is unreactive because Cl- is a good leaving group. True or false?
False - it is very reactive
Are amides reactive or unreactive?
Very unreactive
NH2 can be used as a nucleophile and can react with any acid _______ or ________
chloride
anhydride
Ethanol doesn’t get excreted, it gets metabolised. It gets oxidised using ____________ to form acid aldehyde
alcohol dehydrogenase
Aldehyde dehydrogenase oxidises acid aldehyde to give ___________ which causes weight gain
acetic acid
Why is methanol toxic?
it is processed by alcohol dehydrogenase to give formaldehyde which causes death and blindness
Formaldehyde cannot be further processed as aldehyde dehydrogenases are much more specific than alcohol dehydrogenases. True or false?
True
What is used to treat methanol poisoning and ethylene glycol poisoning?
Whisky
ethanol -> acid aldehyde. Which enzyme is responsible for this oxidation?
alcohol dehydrogenase
acid aldehyde -> acetic acid. Which enzyme is responsible for this oxidation?
aldehyde dehydrogenase
Does alcohol dehydrogenase prefer to oxidise ethanol or non-ethanol alcohols?
ethanol
Is H- a good or bad leaving group?
Bad
Which is more reactive, acid chloride or acid anhydride?
chloride
which is more reactive amides or esters and COOH?
esters and COOH
The grignard reaction is a way of forming new _________ bonds
carbon-carbon
In the grignard reaction, what acts as the nucleophile?
carbon
The alpha carbon refers to which carbon?q
the carbon next to the carbonyl
What is an e.g. of an alpha carbon reaction?
bromination of a carbonyl
What type of reaction is most important for drug synthesis?
substitution
What are the three types of reactions that carbonyls do?
substitution
addition
substitution at alpha carbon
What are the possible leaving groups in nucleophilic substitution reactions?
Cl, Br, I, tosylate
What is the biggest barrier for SN2 reactions?
steric hinderance - the more groups around the leaving group, the slower the rate of reaction
In SN2 both the nucleophile and substrate are involved in the rate determining step. True or false?
True
In a mechanism, what do square brackets and a sigma complex indicate?
A transition state
In SN2 mechanisms, there is a complete racemisation at the carbon. True or false?
False - there is a complete inversion at the carbon
How many steps are there in an SN2 reaction?
One step
How many steps are there in an SN1 reaction?
Two steps
If a leaving group is attached to an alkene or alkyne, will SN1 or SN2 reactions take place?
No - reactions only take place for alkyl halides
What is the biggest barrier for SN1 reactions?
Stability of carbocation
What happens in the first step of SN1 reactions?
Leaving group leaves upon which a carbocation is formed
What happens in step 2 of SN1 reactions?
A nucleophile attacks the carbocation
The carbocation intermediate in SN1 reactions is planar. True or false?
True
In SN1 reactions there is complete racemisation at carbon. True or false?
True
In SN1 reactions, only one side of the compound is accessible to the nucleophile. True or false?
False - both sides of compound are equally accessible to the compound
In SN1 reactions, rate of reaction is dependent on the nucleophile. True or false?
False - it is independent - nucleophile is not involved in rate determining step
What does acylation mean?
Adding a ketone group
When a monosubstituted benzene reacts with an electrophile, substitution can be three things…
ortho
meta
para
ortho is a 1,4 substitution. True or false?
False - it’s a 1,2 substitution
1,4 substitution is called?
para
What position is meta substitution?
1,3
electron donating substituents give rise to which regioselectivity?
ortho
para
electron withdrawing leads to which regioselectivity?
meta
Which is more preffered, Friedel-Crafts acylation or alkylation?
acylation
