反应详情

A solution of the product from Example 16 (0.53 g, 1.32 mmol) in 3N HCl (50 mL) was treated with oxalic acid (0.25 g, 1.98 mmol) and refluxed for four hours. After cooling to room temperature, the precipitate was filtered, suspended in water (70 mL), heated to 80° C. and basifyed to pH 8. The solids were filtered, and dried to give the title compound in two crops [125 mg, mp=293-297° C. (dec.)] and [33 mg, mp=263-266° C. (dec.)] yielding 34%.

1. temperaturerefluxed for four hours
2. filtrationthe precipitate was filtered
3. temperatureheated to 80° C. and basifyed to pH 8
4. filtrationThe solids were filtered
5. customdried