Application of Methylamine hydrochloride 593-51-1.

   Methylamine hydrochloride also known as monomethylamine hydrochloride, colorless plate crystal. Soluble in water, ethanol, insoluble in ether, acetone and chloroform. It is hygroscopic and irritating. It is produced by the action of methylamine with hydrochloric acid.

   Methylamine hydrochloride is used in medicine, dyes and so on. Examples of its application are as follows:

(1) Preparation of 3-methylamino-1 -(2-thiophenyl) -1-propyl alcohol using 2-acetyl thiophene, paraformaldehyde and methylamine hydrochloride. The method of the invention is to directly convert the dimer to 3-methylamino-1 -(2-thiophenyl) -1-acetone hydrochloride and dimer without separating, and then reduce the dimer to the target compound 3-methylamino-1 -(2-thiophenyl) -1-propyl alcohol after directly converting the dimer to 3-methylamino-1 -(2-thiophenyl) -1-acetone hydrochloride. The method has the advantages of simple operation, easy control, high yield and low cost.

(2) A solvent blue 78 was prepared by using methanol aqueous solution as the reaction solvent, fatty alcohol polyoxyethylene ether as the dispersant, 1, 4-dihydroxy-anthraquinone and methylamine hydrochloride as the main raw materials, and 1, 4-dihydroxy-anthraquinone cryptochroma as the initiator or catalyst. The target product solvent blue 78 was obtained through condensation reaction in closed kettle. The invention uses methylamine hydrochloride to replace volatile liquid monomethylamine without producing high-concentration nitrogen-containing wastewater; The aromatic amination of 1, 4-dihydroxy-anthraquinone in the invention uses Ping ping plus O as the dispersant and 1, 4-dihydroxy-anthraquinone as the catalyst, and the yield of the product is increased from about 70% to more than 91%.

(3) Preparation of an isotope labeled sulfamebarb D3, the aqueous solution of methylamine hydrochloride -D3 was added to dimethyl dithiocarboxylate solution by drops, and the reaction resulted in the intermediate S-methyl-n-methylcarboxylate dimethyl ester. The Intermediates were slowly introduced into Cl2 at low temperature, and acid captulifier and m-cresol were added successively to prepare the marker sulfamebarb -D3. Compared with the prior art, the invention has the advantages of simple deuterium-generation isotope labeling process, high yield, undiluted isotope abundance, and suitable for laboratory production of sulfamwei-D3.

(4) 3-methylamino-1-phenylpropyl alcohol was prepared by using acetophenone, paraformaldehyde and methylamine hydrochloride as raw materials. It was heated to 60~100℃ with alcohol as solvent in a closed container for reaction. After concentration, it was cooled and crystallized to obtain 3-methylamino-1-phenylacetone hydrochloride; Then, the solution of 3-methylamino-1-phenylpropanol hydrochloride was reduced by catalysis in solvent. The solution was adjusted to pH 9~14 by liquid alkali, and 3-methylamino-1-phenylpropanol was obtained by extraction, solvent recovery and recrystallization of cyclohexane. In the process of the 3-methylamino-1-phenylpropanol hydrochloride solution being reduced under catalytic conditions, the Rennie nickel catalyst was used for hydrogenation reduction. The Rennie nickel catalytic hydrogenation reduction conditions were as follows: The hydrogen pressure is 0.3~1.5MPa and the temperature is 25~80℃. The invention has the characteristics of high yield, good quality, low production cost and less discharge of three wastes.