β-Nitrostyrene reduction using Zinc and Hydrochloric Acid - [PEA.HCl]

Описание: This video goes over the synthesis of β-Phenethylamine hydrochloride;
a human neurotransmitter, using Zinc and Hydrochloric Acid.

The reduction that takes place is supposedly due to the [Zn/H2/Both] starting the formation of the NO2 group to an mixture of enamine and imine equilibrium, which the Zn2+ in solution carries the electron transfer with H2 to reduce the imine to amine; as per standard electron transfer reductive imine amination.
As the imine is used up; more enamine converts to imine, which is reduced, causing more enamine to convert to imine and so forth.
Although, the exact mechanism has not been officially confirmed; this is the most recognized way that the reaction is thought to proceed.

This is then carefully basified, which results in the PEA.HCl in solution freebasing and is extracted with IPA, filtered, dried over Na2SO4, then salted to form the respective PEA.HCl salt once more, isolated and washed.

In this run I use 10.1g of β-Nitrostyrene and get 8.30g β-Phenethylamine.HCl;
or a yield of 79.3% to a sparkling white crystalline product.

This will generally work with most β-Nitrostyrenes regardless of aromatic rings or functional groups; as Zn/HCl is consistently selective for NO2 functional group reductions to NH2; without interacting with other groups.

This is the source of literature provided for reaction scheme;
"Modern Synthetic Reactions 2nd Ed - Herbert O. House, PAGE 211"
"Reduction of aromatic nitro compounds to amines using zinc and aqueous chelating ethers: Mild and efficient method for zinc activation - /doi/10.2478/s11696-012-0195-6/"
"Method for reducing aromatic nitro groups - EU Patent - EP0347136A2"
"Nitro Reduction - Common Conditions - (CommonOrganicChemistry)"

[Timestamps]
Intro: (0:00)
Preparation: (0:15)
Zinc Reaction: (1:46)
Workup: (9:45)
Extraction: (11:35)
Drying: (13:12)
Salting: (16:00)
Evaporation: (17:26)
Crude Yield: (19:30)
Cleaning: (19:58)
Final Yield: (22:24)