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