13-benzenesulfonylhydrazone anthracyclines useful in producing improved
yields in the synthesis 13-deoxyanthrcyclines, and an improved method of
reducing 13-benzene-sulfonylhydrazone anthracyclines to
13-deoxyanthrcyclines wherein the reduction reaction is maintained at
temperatures of about 55.degree. C. to 64.degree. C. without stirring or
agitation. The reaction is completed with the addition of aqueous
bicarbonate which forms the 13-deoxyanthracycline and precipitates. The
precipitates are filtered and the precipitate and filtrate are extracted
separately with organic solvents. The crude 13-deoxy anthracycline can be
converted to 5-imino-13-deoxy anthracycline by reaction with methanolic
ammonia. The reaction can also be performed with an acidic pyridinium
salt instead of a strong acid so that neutralization of the reaction or
extraction of the product is not necessary, thereby facilitating
purification.