Summary: Novel 2-thio substituted 1,3,4-oxadiazole derivatives of santonic acid (13-18) were synthesized.
Keywords: a-Santonin; Santonic acid; Antibacterial activity; Antifungal activity.
Experimental Procedure for the Microwave Assisted Synthesis of Santonic Acid (3)
Santoninic acid was then rearranged in situ to santonic acid 3.
Experimental Procedure for the Microwave-Assisted Synthesis of Imidazolyl derivative of Santonic Acid (4)
A mixture of santonic acid (1 mmol), 1,1- carbonyl diimidazole (1 mmol) in acetonitrile (2 ml) and triethylamine (1 mmol) as a base were taken in microwave vial (2-5 ml).
Imidazolyl derivative of santonic acid 4 (1 mmol) was taken in hydrazine hydrate (2 ml) into a microwave vial (2-5 ml) and irradiated for 20 min with each pulse of 10 sec after keeping into the microwave cavity at a set temperature, pressure and power control.
Santonic carbohydrazide (1 mmol), 95% ethanol (2 ml), NaOH (1 g) and CS2 (1 ml) was taken in a microwave vial, equipped as previously described, irradiated for 20 minutes with each pulse of 10 sec.
Santoninic acid was detected between the reaction first and second step by monitoring the TLC and characterized after a mini workup as described in the experimental procedure, however, on long it was rearranges in situ into the more stable, thermodynamic product santonic acid 3 which is a isomer of santoninic acid.
Furthermore, santonic acid was treated with 1,1-carbonyl diimidazole (CDI) in order to convert into its acyl imidazole derivative 4.
Hydrazinolysis of acyl imidazole derivative 4 was carried out to furnish santonic carbohydrazide 5 by treating the acyl imidazole derivative 4 with hydrazine hydrate.