Acetate → Gly-Phe-NH2

Participants

Reaction Conditions

Reaction Steps

In 12.5 ml. of dimethylformamide (DMF) there was dissolved 131 mg. (250 μmoles) of a labelling cyanine dye shown by formula III below: ##STR22## and the solution was cooled to -15° C. To the solution was added 33 μliters (250 μmoles) of isobutyl chloroformate, and after further adding thereto 35 μliters (250 μmoles) of triethylamine, the reaction was performed for 5 minutes at a temperature of -15° C. to -10° C. Then, after further adding 70 mg (250 μmoles) of the acetate of glycylphenylalanylamide and 35 μliters (250 μmoles) of triethylamine to the reaction mixture, reaction was further performed for one hour at 0° C. and then for one further hour at room temperature. To the reaction mixture obtained was added 25 ml of ethyl acetate and the precipitates formed were recovered by filtration and washed with ethyl acetate. The powder thus obtained was repeatedly purified by a silica gel column chromatography (eluate: a 3:1 mixture of chloroform and methanol) and then recrystallized from a 1:1 mixture of chloroform and methanol to provide 128 mg (yield of 71%) of glycylphenylalaninamide the N-terminal of which has been modified or labelled by the dye of formula III.

Provenance & Evidence