US Patent 7772379 Compositions and processes for preparing 13-deoxy-anthracyclines

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° C. to 64° 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.