Figure 4.
Some of UA derivatives. 1, 25–27; 1: R1 = H; R2 = H; R3 = OH; 25: R1 = OCCH3; R2 = H; R3=OH; 26: R1 = OCCH3; R2 = O; R3 = NHC6H5; 27: R1 = OCH2CH2CH3; R2 = H; R3 = NHCH2CO2CH3.
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