反应详情

Crystalline dimeric formaldehyde conjugate of doxorubicin was prepared in a similar manner as was crystalline dimeric formaldehyde conjugate of daunorubicin except for the crystallization step. For a procedure starting with 40 mg, the crude product was dissolved in 1.3 mL of chloroform diluted with 27 mL of 3:1 ethyl acetate:hexane. The resulting solution was dispensed in 3 mL aliquots into nine 5 mL vials and allowed to stand undisturbed and stoppered in the dark for 3 days. The resulting crystals grew as red hexagonal tubes on the glass. The crystals were washed with ethyl acetate, collected, and dried under vacuum (0.1 Torr) to yield 14.5 mg (37%) of pure dimeric formaldehyde conjugate of doxorubicin. Anal. (C57H58N2O22)C, H, N. The crystalline material showed the same 1H NMR spectral properties as the amorphous material. The positive ion ESI mass spectrum of a sample in chloroform/methanol supported the structure in Scheme III for the dimeric formaldehyde conjugate of doxorubicin.

1. customexcept for the crystallization step
2. dissolutionthe crude product was dissolved in 1.3 mL of chloroform
3. additiondiluted with 27 mL of 3:1 ethyl acetate
4. washThe crystals were washed with ethyl acetate
5. customcollected
6. customdried under vacuum (0.1 Torr)