4,5,6,7-Tetrahydro-N6-propyl-2,6-benzothiazolediamine → HCID 86591096, compound

Participants

Reaction Steps

5 g of (±)2-amino-6-propylamino-4,5,6,7-tetrahydrobenzothiazole was dissolved in 25 ml of methanol and 4.0 g of L(+)-tartaric acid was added under stirring. The mixture was cooled and the white crystals were filtered off, washed with methanol and dried to yield 4.8 g of pramipexole tartrate. The crystals were dissolved in 10 ml of water and concentrated hydrochloric acid was added to dissolve the solid. The solution was cooled to 10° C. and a solution of 10 g of potassium hydroxide in 10 ml of water was added. The mixture was stirred for 30 minutes and the white crystals were removed by filtration and washed with cold water. The crystals were redissolved in 7 ml of ethanol and gaseous hydrogen chloride was bubbled through the solution at 10° C. After 1 hour of stirring, the precipitated solid was separated by filtration, washed with cold ethanol and dried to yield 2.1 g of white crystals. The product is identical with pramipexole dihydrochloride by NMR and has optical rotation [α](20,D)=−48,78° (c=1, MEOH)

Provenance & Evidence