Reactions of 4-chloro-3-nitrocoumarin with a variety of nucleophiles produced a number of novel substitutedcoumarins. Hard and borderline nucleophiles exclusively substitute chlorine in position 4, while softnucleophilessubstitute the nitro group in position 3 (except for iodide) of the title compound. This result of the nucleophilicsubstitution of 4-chloro-3-nitrocoumarin is rationalized in terms
Herein, we describe the synthesis and complete assignment of the (1)H and (13)CNMRchemicalshifts of a series of antimicrobial 4-arylamino-3-nitrocoumarin derivatives based on a combination of (1)H and (13)CNMR, (1)H-(1)H-COSY, NOESY, HSQC and HMBC experiments. Conformational effects upon the chemicalshifts of the coumarin moiety arising from the anisotropy of the aryl side group are briefly discussed