Dimethylamine → Topotecan

Participants

Reaction Steps

A mixture of 10-hydroxycamptothecin (728 mg 2.0 mmol), prepared as described in Example 2, in glacial acetic (50 mL), ethanol (20 mL), 37% aqueous formaldehyde (3 mL) and 40% aqueous dimethylamine (3 mL) was stirred at room temperature for 20 h. The solvents were removed under reduced pressure; the residue was heated at 50° under high vacuum for 2 h and triturated with isopropanol (10 mL) to precipitate the title compound (561 mg, 64%) as a yellow solid. FAB mass spectrum: m/e 422 (MH+). 1H NMR (CDCl3 /CD3OD) δ1.0 (t, 3), 1.9 (m, 2), 2.5 (s, 6), 4.3 (s, 2), 5.2 (s, 2), 5.4 (q, 2), 7.6 (s, 1), 7.7 (q, 2), 8.5 (s, 1).

Provenance & Evidence