Cysteamine Hydrochloride → 3-[(2-Aminoethyl)thiomethyl]isothiazole hydrochloride

A solution was prepared by the gradual addition of cysteamine hydrochloride (2.03 g) to sodium (0.83 g) dissolved in ethanol (50 ml) with stirring at 0° under a nitrogen atmosphere. After stirring for 2 hours at 0° 3-bromomethylisothiazole (3.2 g) was added dropwise over 15 minutes at 0°, the reaction mixture subsequently being set aside overnight at room temperature. Following acidification to pH 3.5 with hydrochloric acid, concentration and re-evaporation with ethanol, the residue was dissolved in ethanol, filtered and concentrated to yield 3-[(2-aminoethyl)thiomethyl]isothiazole hydrochloride (3.5 g). This was converted directly to the free base by treatment with aqueous potassium carbonate and extraction with ether. The extracts were dried over magnesium sulphate, dried and concentrated to yield the amine base as an oil (1.56 g).

1. additionwas added dropwise over 15 minutes at 0°
2. concentrationwith hydrochloric acid, concentration and re-evaporation with ethanol
3. dissolutionthe residue was dissolved in ethanol
4. filtrationfiltered
5. concentrationconcentrated

ORD record

ord-7b3e8c891b20468799ed475ec9007763

Source dataset

uspto-grants-1981_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04284640