How do you synthesis Benzocaine?
How do you synthesis Benzocaine?
Synthesis of benzocaine: Into a 100 ml flask, mix 1.25 g of p-aminobenzoic acid hydrochloride, 10 ml of EtOH, and 0.5 ml H2SO4 (conc.). Heat the mixture at reflux for 2 h. After cooling the mixture, neutralize with an aqueous sodium carbonate solution (10%).
What is the starting material for benzocaine synthesis?
The classic, optimal way of benzocaine synthesis is the reduction of the nitro group of the ethyl ester of 4-nitrobenzoic acid to benzocaine by hydrogen, which generates directly in the reaction medium by the reaction of iron filings with dilute acids [24–26].
How do you synthesize P-aminobenzoic acid?
As shown in Scheme 1, in order to prepare p-aminobenzoic acid, toluene is first nitrated to synthesize ortho-nitrotoluene and para-nitrotoluene, which are separated, and then p- Nitrotoluene is oxidized to prepare p-nitrobenzoic acid, and the nitro group of p-nitrobenzoic acid is synthesized by reduction using an …
What is the pKa of benzocaine?
Benzocaine is a unique local anesthetic because it does notcontain a tertiary amine. The pKa of the aromatic amine is 3.5ensuring that benzocaine is uncharged at physiological pH.
How do you synthesize benzocaine from P nitrotoluene?
Principle: In step 1 common reduction of aromatic para-nitrobenzoic acid by tin and hydrochloric acid to para-aminobenzoic acid and in step 2 esterification of para-aminobenzoic acid by sulphuric acid and ethanol to benzocaine occurring called Fischer esterification.
How is benzocaine synthesized industrially from P nitrobenzoic acid?
Benzocaine can be prepared by esterification using 4-aminobenzoic acid and ethanol. It can also be prepared by reduction of ethyl 4-nitrobenzoate to the amine. In industrial practice, the reducing agent is usually iron and water in the presence of a little acid.
Is 4 aminobenzoic acid a Zwitterion?
o and p-aminobenzoic acids do not exist as a Zwitter ion. The lone pair of electrons on the −NH2 group is donated towards the benzene ring due to resonance effect. As a result, acidic character of -COOR group and basic character of −NH2 group decrease.
What is benzocaine made of?
Benzocaine is a chemical compound derived from para-aminobenzoic acid and ethanol. It is a white, odorless, crystalline powder. It acts on neuronal membranes and blocks nerve signals in the body. Its numbing effects are temporary.
What is the Iupac name for Benzocaine?
Benzocaine is an ester, a compound made from the organic acid PABA (para-aminobenzoic acid) and ethanol….3D Structure for HMDB0004992 (Benzocaine)
| Value | Source |
|---|---|
| Ethyl aminobenzoate | ChEBI |
| Ethyl p-aminobenzoate | ChEBI |
| Ethyl p-aminophenylcarboxylate | ChEBI |
| p-(Ethoxycarbonyl)aniline | ChEBI |
How is 1 4-dihydropyridine synthesized?
Hantzsch 1,4-dihydropyridine and polyhydroquinoline derivatives were synthesized in excellent yields in aqueous micelles. The reaction is catalyzed by PTSA and strongly accelerated by ultrasonic irradiation. A. Kumar, R. A. Maurya, Synlett, 2008 , 883-885.
What is the history of pyridine synthesis?
The first synthesis of 1,4-dihydropyridines was reported by Arthur Hantzsch in 1882. 26 He observed that in the process of synthesizing pyridine by a one pot three-component condensation reaction of acetoacetic ester, aldehyde and ammonia, an intermediate 1,4-dihydropyridine (1,4-DHP) 94 is formed, which could be isolated easily.
How many dihydropyridines are produced from aluminum chloride promoted Hantzsch reaction?
An aluminum chloride promoted Hantzsch reaction of a wide range of N -tosylhydrazones provides a series of 1,4-dihydropyridines (1,4-DHPs) in good yields. H. Wang, M. Tang, Synthesis, 2017, 49, 4893-4898.
What is the percentage of dihydropyridine in methanol in THF reaction?
They observed that reaction in THF at 0 °C gave a mixture of dihydropyridines containing about 35–40% of 1,4-dihydropyridine along with the 1,2-dihydropyridine. However, the amount of 1,4-isomer can be reduced to 2–4% by performing the reaction in methanol at −70 °C giving 1,2-DHP in 86–88% yields ( Scheme 1 ).
