(+/-)-Camptothecin → 8-Methyl-7-propanoylindolizino[1,2-b]quinolin-9(11H)-one

Participants

Reaction Steps

A sample of 4.6 g of 4-ethyl-4-hydroxy-1H-pyrano[3',4':6,7]-indolizino[1,2-b]quinolin-3,14(4H,12H)-dione [(20 S) camptothecin] was stirred with 46 ml of N,N-dimethylformamide. The suspension was heated at reflux, and the disappearance of starting material was monitored by HPLC (C18 reverse phase column, 20-25% acetonitrile:water mobile phase, perchlorate buffer at pH approximately 3.0). The reaction was monitored by UV detection at a wavelength of 228 nm. The only responses detected under these conditions were a peak for N,N-dimethylformamide near the solvent front, a peak for the starting material and a peak for the desired product with a retention time of approximately 3.2 relative to the starting material. The reaction was heated until consumption of the starting material was complete (approximately 8 days). After cooling to ambient temperature the solid product was collected by filtration, and washed with methanol. After drying under vacuum to a constant weight 3.48 g (87%) of product, m.p. 233°-234° C. was obtained.

Provenance & Evidence