反应详情

The product from Step 3 (200 mg, 1.1 mmol) in methanol (4 ml) and 2N hydrochloric acid (4 ml) was treated portionwise with sodium nitrite (150 mg, 2.2 mmol) and stirred at room temperature for 2 hours. The pH of the mixture was adjusted to 12 by addition of 50% sodium hydroxide solution and a 50% solution of hydroxylamine in water (3 ml) was added. The mixture was heated at 90° C. for 2.5 hours and the reaction allowed to cool to room temperature. The resulting precipitate was filtered and dried in vacuo to afford the title compound (110 mg, 43%); MS (ES+) m/e 231 [M+H]+.

1. temperatureThe mixture was heated at 90° C. for 2.5 hours
2. temperatureto cool to room temperature
3. filtrationThe resulting precipitate was filtered
4. customdried in vacuo