HCID 178511198, compound → Carnosine

Participants

Reaction Conditions

Reaction Steps

A 1-liter pressure autoclave was initially charged with 4.50 g of Raney cobalt (doped with 0.3% iron) in a mixture of 285 g of conc. ammonia/methanol (m/m=1.9:1). The autoclave was closed and flushed twice with 40 bar of nitrogen and then pressurized with 45 bar of hydrogen, and the mixture was then heated to 100° C. This was followed by metering in a solution of 30.0 g (0.135 mol) of (S)-2-(cyanoacetylamino)-3-(1H-imidazol-4-yl)propionic acid (prepared according to Example 3) in a mixture of 285 g of conc. ammonia/methanol (m/m=1.9:1) over the course of one hour. After further reaction at 100° C. for one hour, the reaction mixture was cooled to room temperature. The autoclave was depressurized and the catalyst was filtered off. An in-process HPLC analysis showed that the reddish-brown reaction solution (310.5 g) contained 9.57% (m/m) carnosine, corresponding to a selectivity of 97% for complete conversion.

Provenance & Evidence