Methylamine hydrochloride

Description

Methylamine Hydrochloride is a colorless organic solid that has an odor similar to that of fish and is used as an essential part for the synthesis of a wide variety of commercial compounds such as ephedrine, theophylline and other intermediates for a wide range of agricultural chemicals, including herbicides, fungicides, insecticides, biocides, and miticides. Methylamine hydrochloride is also a key ingredient in the synthesis of methamphetamine

Chemical properties

white to light tan solid

The Uses of Methylamine hydrochloride

Methylamine is used as a building block for synthesizing other organic compounds and is on the DEA watchlist for chemical precursors due to its clandestine use in the manufacture of the drugs MDMA (ecstasy) and methamphetamine. Its HCl salt forms white deliquescent crystals and is often used as a substitute for the aqueous solution in various synthesis preparations. Methylamines serve directly as catalysts or as raw materials to produce other compounds with catalytic activity. They are also used as fuel additives to improve engine performance in various ways. Trimethylamine, a derivative, is employed in the production of paper chemicals. One of the most diverse applications of methylamines is in the manufacture of intermediates for pharmaceuticals.

Definition

ChEBI: The hydrochloride formed from methylamine.

Preparation

Methylamine hydrochloride is prepared by heating a mixture of aqueous formaldehyde and ammonium chloride; the residual water and the formic acid produced in the reaction are removed via vacuum distillation. This leaves behind solid methylamine hydrochloride. The solid is then purified by organic extractions and additional vacuum distillations. Methylamine gas for the reaction with P2P is generated in situ by heating the hydrochloride salt with sodium hydroxide. Alternatively, methylamine can be liberated from the hydrochloride with base and collected in a cold finger or flask immersed in a dry ice bath.

Pharmacology

Methylamine hydrochloride reduces blood pressure in both normotensive and hypertensive individuals. It has a gradual onset of action (1/2 to 2 hours) and a long-lasting effect (usually 6 to 12 hours or more). A small oral dosage often produces a smooth and predictable reduction of blood pressure. Although this antihypertensive effect is predominantly orthostatic, the supine blood pressure is also significantly reduced.

Description

Methylamine hydrochloride can be used as a reactant in various synthetic processes. It can synthesize betahistine via an aza-Michael reaction with 2-vinylpyridine in water. It also facilitates the formation of azatripyrrolic and azatetrapyrrolic macrocycles by reacting with pyrrole and formaldehyde through a base-catalyzed Mannich reaction. Additionally, it can produce tetrahydropyridines via an aza-Diels–Alder reaction with dienes and aldehydes, and synthesize N-methylsecondary arylamines from aryl chlorides through a nickel-catalyzed amination reaction.

Solubility in organics

Very soluble in N,N-Dimethylformamide,Soluble in methanol,Sparingly soluble inglacial acetic acid, Very slightly soluble inchloroform.

Solubility in water

The experimental water solubility of Methylamine hydrochloride at 20 ℃ was 1080mg/L. Methylamine hydrochloride is highly soluble in water.

storage

Keep in a dry, cool and well-ventilated place. Keep container tightly close

Purification Methods

Crystallise the salt from n-butanol, absolute EtOH or MeOH/CHCl3. Wash it with CHCl3 to remove traces of dimethylamine hydrochloride. Dry it under vacuum first with H2SO4 then P2O5. It is deliquescent; store it in a desiccator over P2O5. [Beilstein 4 IV 122.]