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    • 5. 发明专利
    • DE2130280A1
    • 1971-12-23
    • DE2130280
    • 1971-06-18
    • RICHTER GEDEON VEGYESZET
    • TUBA ZOLTAN DRGEB SZABO MARIA BOR
    • C07J9/00C07D221/18C07J73/00C07D101/00
    • A process for the preparation of cholestane derivatives and their salts, which contain a nitrogen atom in position 2 or 3 of the general formula i ** (see formula) ** Wherein a and b represent carbonyl, methylene, imino or N-methylimino groups, with the restriction that, within the same compound, a and b are different, but a or b always represent an imino, or N-methylimino, group by the fact that a compound of the general formula ii ** (see formula) ** Wherein x and y represent a carbamoyl and/or carbomethoxy or carboethoxy group, but in at least one compound, it is reacted with lead tetraacetate and then the compound thus formed is subjected to a ring closure reaction in the presence of a alkali metal hydroxide or an alkali metal alcoholate and then, if desired, the lactams of the general formula i are subjected: a) to methylation with methyl iodide in the presence of potassium tert-butylate and, if required, to reduction with sodium hydride-bis- (2-methoxy-ethoxy) -aluminium; or b) reduction with a complex metal hydride, and subsequent methylation with formaldehyde in a formic acid medium and, if desired, the salt of the base thus obtained is formed. (Machine-translation by Google Translate, not legally binding)