N,N'-Dicyclohexylurea → Tyramine

Participants

Reaction Conditions

Reaction Steps

Formation of the tyramide of compound 111, is as follows. N-hydroxysuccinimide (33 mg) is dissolved in the reaction mixture prepared above by heating to 70° C., then dicyclohexylcarbodiimide (61 mg) is added. This is reacted at 70° C. for 90 minutes, an additional amount (6 mg) of the carbodiimide is added and the reaction is continued for another 30 minutes. The mixture is cooled to 0° C. and the precipitated dicyclohexylurea is settled by centrifugation. The supernatant, containing 6-(-4'-N-hydroxysuccinimidyl carboxy phenyl)-3,8-bis bromoacetamidyl-5 -methylphenanthridinium chloride (IV) is recovered. A solution of tyramine [4-(2'-amino)ethylphenol] (1.0 g) in water (5 ml) is formed by bringing it to pH 7 by addition of concentrated HCl. This solution is added to the supernatant containing compound IV and reacted at room temperature for one hour. This mixture is then reduced to a red oil by evacuation at 60° C., and is then extracted with water to remove excess tyramine. Compound (VI) is then recrystalized from ethanol-acidified with HCl.

Provenance & Evidence