p-Toluenesulfonic acid → Cositecan

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(2-amino-phenyl)-3-trimethylsilanyl-propan-1-one (3) (34 mg) and CDE ring moiety (4) (24 mg) in acetic acid (0.5 mL) and toluene (1 mL) was added p-toluenesulfonic acid (1 mg). The reaction solution was stirred for 20 hours at 100° C. After cooling to room temperature, the reaction solution was concentrated under reduced pressure and the residue was washed with hexane (10 mL), water (10 mL), and a mixture of acetone (5 mL) and hexane (5 mL). The yellow solid was evaporated to dryness in vacuo to yield 39 mg (98% Yield) of BNP1350 (Karenitecin; Cositecan; 7-(2′-trimethylsilyl)ethyl camptothecin; IUPAC Nomenclature: (4S)-4-ethyl-4-hydroxy-11-[2-(trimethylsilyl)ethyl]-1H-pyrano[3′:4′:6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione).

Provenance & Evidence