| 摘要 |
<p>The present invention provides a method of preparing norelgestromin or norgestimate by reacting the corresponding 3-oxosteroid precursor with hydroxylamine HCl and a base to obtain a reaction mixture forming norelgestromin or norgestimate; monitoring the anti/syn ratio of the norelgestromin or norgestimate produced in the reaction mixture; adding a base to the reaction mixture to neutralize acidity in the reaction mixture when a desired anti/syn ratio is detected; and isolating the norelgestromin or norgestimate. The present invention also provides a process allowing a control of the formation of the anti isomer and syn isomer of norelgestromin or norgestimate by reacting the corresponding 3-oxosteroid precursor with hydroxylamine HCl and a base to obtain a reaction mixture forming norelgestromin or norgestimate; regulating the acidity of the reaction mixture to adjust the anti/syn ratio of the norelgestromin or norgestimate produced in the reaction mixture; adding a base to the react ion mixture to neutralize acidity in the reaction mixture when a desired anti/syn ratio is detected; and isolating the norelgestromin or norgestimate.</p> |
