Hydrochloric Acid → (+)-(4R)-4-(4-aminobutyl)-4,5-dihydro-1,3-thiazol-2-ylamine dihydrochloride

Participants

Reaction Steps

The process is performed as in Example 1, starting with 5.9 g of benzyl (5R)-5-{[(tert-butylamino)carbothioyl]amino}-6-hydroxyhexylcarbamate in 40 cm3 of aqueous 6N hydrochloric acid at a temperature in the region of 100° C. for 3 hours. After concentration of the reaction medium under reduced pressure (5 kPa) at a temperature in the region of 50° C., the residue obtained is taken up in ethanol and then concentrated again under the above conditions. The paste obtained is crystallized by trituration from an ethanol/methanol mixture (8/2 by volume). The crystals are filtered off, washed with acetonitrile and air-dried. 1.3 g of (+)-(4R)-4-(4-aminobutyl)-4,5-dihydro-1,3-thiazol-2-ylamine dihydrochloride are obtained in the form of a white solid melting at 188° C. (αD20=+16.2±0.7 at a concentration of 0.5% in methanol).

Provenance & Evidence