Atracurium Besylate CAS 64228-81-5

0.1mol of 1,5-pentanediol, 0.2mol of triethylamine and 0.1g of 1,2,3-phloroglucinol were dissolved in 100ml of anhydrous benzene, and under vigorous stirring, 0.2mol of 0.2mol was added within 0.5h A solution of acryloyl chloride dissolved in 60 ml of anhydrous benzene. Then add about 100ml of anhydrous benzene and 10ml of triethylamine, and then stir at 50°C for 0.5h. Triethylamine hydrochloride was removed by filtration and the solvent was removed under reduced pressure. The remaining yellow oil was distilled in the presence of a trace amount of p-methoxyphenol in the dark, and the fraction at 90~95°C/1.33Pa was collected to obtain 1,5-pentylene diacrylate with a yield of 61%.

4.43 g of tetrahydropapaverine and 1.30 g of the 1,5-pentylene diacrylate obtained above were dissolved in 15 ml of anhydrous benzene, and stirred and refluxed in the dark for 48 h. The solvent was removed under reduced pressure and the remaining dark red oil was dissolved in 10 ml of chloroform. About 400 ml of ether was added, followed by about 500 ml of saturated oxalic acid in ether to obtain a flocculent white precipitate. Filter, wash with ether and dry. It was recrystallized twice with ethanol to obtain 3.5 g of compound (I) in the form of white powder with a yield of 51% and a melting point of 117-121°C. Compound (I) was dissolved in an aqueous sodium bicarbonate solution and extracted with toluene. After the extract was concentrated, a colorless viscous liquid was obtained, which was compound (II).

0.5 g of dry compound (II) was dissolved in 8 ml of spectrally pure acetonitrile, methyl benzenesulfonate was added, and the reaction was carried out at room temperature for 22 h. With vigorous stirring, the solution was added dropwise to about 450 ml of dry ether. The resulting flocculent white precipitate was collected by filtration, washed with dry ether, and dried under vacuum at 50°C in the presence of phosphorus pentoxide. An off-white powder of atracurium besylate was obtained, with a melting point of 85-90°C.