Ultrasound-promoted synthesis of novel bipodal and tripodalpiperidin-4-ones and silica chloride mediated conversion to its piperidin-4-ols: Synthesis and structural confinements

The ultrasound-promoted synthesis of novel bipodal and tripodalpiperidin-4-ones was carried out by the reaction of 4-piperidone hydrochloride monohydrate with different alkylating and acylating agents. It was preferably reduced to respective piperidin-4-ols by ultrasonic irradiation using silica chloride, which maintains higher yields by acting as an effective supporting polymer. The sterically hindered phthaloyl derivative of piperidin-4-one was synthesized by ultrasonic irradiation which was difficult by conventional methods.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Novel bipodal, tripodalpiperidin-4-ones were synthesized under sonication. ► High percentage of yields was found under sonication than the conventional methods. ► Piperidin-4-ones were reduced using silica chloride/NaBH4 with higher yields. ► Silica chloride/NaBH4 works as an effective catalyst for reduction under sonication. ► Sterically hindered phthaloyl piperidin-4-one was also achieved under sonication.