How are benzodiazepines Synthesised?

Benzodiazepines are generally synthesized by the condensation of o-phenylenediamine (OPDA) with a,b-unsaturated carbonyl compounds, b-haloketones, or with ketones [12] using acidic catalysts which are critical to enhance the condensation process.

How is lorazepam synthesized?

Lorazepam, 7-chloro-4-(o-chlorophenyl)-1,3-dihydro-3-hydroxy-2H-1,4-benzodiazepin-2-one (5.1. 31), is synthesized according to a scheme containing some of the same elements for the synthesis of chlordiazepoxide and oxazepam, and comes from 2-amino-2′,5-dichlorobenzophenone. Reacting this with hydroxylamine gives (5.1.

How is benzodiazepines metabolized?

Metabolism. All benzodiazepines are metabolized by the liver. However, some benzodiazepines (i.e. – lorazepam, oxazepam, and tamazepam) do not go through cytochrome P450 metabolism (Phase I metabolism), and are only metabolized via glucuronidation (Phase II metabolism).

What is the mechanism of action of benzodiazepines?

Benzodiazepines work by enhancing a very important neurotransmitter called GABA (gamma-aminobutyric acid) at the GABA A receptor. This results in the sedative, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle relaxant properties for which the drugs are prescribed.

Which of the following reaction mechanism is involved in synthesis of diazepam?

Method of synthesis 2-amino-5-chlorobenzophenone undergoes cyclocondensation with the ethyl ester of glycine hydrochloride produces 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one.

How do you synthesize Clonazepam?

The synthesis of clonazepam begins with 2-chloro-2′nitrobenzophenon, which is reduced to 2-chloro-2′-aminobenzophenon (9.6. 1) by hydrogen over Raney nickel. The amino derivative is amidated by 2-bromoacetyl bromide to give the bromacetamide (9.6. 2) and is further converted into aminoacetamide (9.6.

How do benzodiazepines work?

Benzodiazepines enhance the action of the neurotransmitter gamma-aminobutyric acid (GABA), which slows down the central nervous system. This produces the calming, sedative effect that helps with anxiety.

What enzyme metabolizes benzodiazepines?

Cytochrome P450
Cytochrome P450(CYP)3A4 is one of the CYP enzymes catalyzing oxidative metabolism, and involved in the metabolism of many drugs. Among benzodiazepines, alprazolam, triazolam, brotizolam and midazolam are mainly metabolished by CYP3A4, and quazepam, diazepam and flunitrazepam are partly metabolised by this enzyme.

What are the pharmacokinetics of benzodiazepines?

Benzodiazepines are extensively bound to plasma proteins (80–98%), resulting in a small ‘free fraction’ which can cross the blood-brain barrier. Although benzodiazepines are well absorbed after oral administration, midazolam has the largest first-pass elimination by the liver.

How do benzodiazepines work on GABA receptors?

Benzodiazepines produce their effects by enhancing the binding of GABA to its receptor. GABA activates the chloride ion channel, allowing chloride ions to enter the neuron. The flow of chloride ions into the neuron hyperpolarizes and inhibits the neuron.