The key intermediate was prepared by cyclization of compound with ethyl acetoacetate in presence of glacial acetic acid.
The key intermediate pyrazolone considered as a cyclic amide and hydrogen atom attached to C4 atom should be appreciably labile to participate in the Mannich condensation.
The one pot reaction preparation, spectral analysis, and molecular modeling experiments on the new 3,4-annelated coumarin systems with bioactivity associated structural features are described.
These provided the insight into the equilibrium of the respective tautomeric forms making possible the reconciliation of previously published spectral data with the structure assignments as well as the correction of erroneously established structures.
This review focus on therapeutic importance of coumarins along with various methods of synthesis INTRODUCTION: Coumarins are cinnamic acid derived phenolic compounds which are found in fungi, bacteria and plants, particularly in edible plants of different botanical families.
The name coumarin is derived from `coumarou’, which is the vernacular name of Tonka bean (.
Coumarins can be subdivided into two categories: (1) benzo-α-pyrone commonly called as coumarins (2) benzo-ϒ-pyrones called as chromones or flavanoids, differs only in the position of carbonyl group on the heterocyclic system. 1: 2-H CHROMEN-2-ONE COUMARIN Some important compounds isolated from coumarin are Warfarin, Acenocoumarol, Armillarisin A, Novobiocin, Clorobiocin, Hymecromone etc.
coumarin and its derivatives could be synthesized in laboratory by Pechmann reaction, perkin reaction, Reformatsky reaction and Knovenegal reaction.
Some important coumarin members have been isolated from microbial sources e.g. 6 Pharmacological activities: Antimicrobial activity: Coumarin derivatives are having promising antimicrobial activities as per recent literature survey, details of which have been presented as given below: Rama Ganesh by agar cup diffusion method.
DMF was used as blank, Streptomycin was used as anti-bacterial standard and Clotrimazole was used as anti-fungal standard drug at concentration of 1000μg/ml.