4-Nitro and 7-nitro propranolol have been recently synthesized and characterized by us. (±)-4-NO₂-propranolol has been shown to act as a selective antagonist of 6-nitrodopamine (6-ND) receptors in the right atrium of rats. As part of our follow-up to this study, herein, we describe the first synthesis of (±)-3-nitroatenolol as a probe to evaluate the potential nitration of atenolol by endothelium. Chiral chromatography was used to produce pure enantiomers. By using Riguera’s method, which is based on the sign distribution of ΔδH, the absolute configuration of the secondary alcohol was determined.

6-Nitrodopamine is an endogenous catecholamine responsible for numerous biological activities. Here, an improved method for the synthesis of both 6-nitrohomovanillic acid (6-NHVA) and its regioisomer 5-nitrohomovanillic acid (5-NHVA) is reported. The developed one-step synthetic procedures ensured the efficient preparation of the target compounds in good yields. Comprehensive structural characterization was achieved through one- and two-dimensional NMR studies and by high-resolution mass spectrometry (HR-MS/MS). The presence of both substances was identified in human amniotic fluid by LC-MS/MS.