Fig shows the absorbance trend of DDQ

Similarly, 1H NMR of procaine in CD3CD2OD ∂ CH3 3H(t) 1.01 ppm, 1.31 ppm before and after equimolar addition of DDQ; 1H NMR of atenolol in CD3CD2OD ∂ CH3 3H(d) 1.01 ppm, 1.37 ppm before and after equimolar addition of DDQ (spectra not shown). The drift stopped after the addition of an equimolar quantity of DDQ (nested graphs in Fig.