Efficient synthesis of piperazinyl amides of 18ß-glycyrrhetinic acid.
Beilstein J Org Chem
; 16: 798-808, 2020.
Article
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| MEDLINE
| ID: mdl-32395183
ABSTRACT
In the present study, a practical method to prepare piperazinyl amides of 18ß-glycyrrhetinic acid was developed. Two main procedures for the construction of important intermediate 8 are discussed. One procedure involves the amidation of 1-Boc-piperazine with 3-acetyl-18ß-glycyrrhetinic acid, prepared by the reaction of 18ß-glycyrrhetinic acid with acetic anhydride without any solvent at 130 °C. The other procedure to prepare compound 8 involves the amidation of 18ß-glycyrrhetinic acid followed by the esterification with acetic anhydride. Finally, compound 8 underwent N-Boc deprotection to prepare product 4. To ascertain the scope of the reaction, another C-3 ester derivative 17 was tested under the optimized reaction conditions. Furthermore, the reasons for the appearance of byproducts were elucidated. Crystallographic data of a selected piperazinyl amide is reported.
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Bases de datos:
MEDLINE
Idioma:
En
Revista:
Beilstein J Org Chem
Año:
2020
Tipo del documento:
Article
País de afiliación:
China