Modified syntheses of dopamine-4-sulfate, epinephrine-3-sulfate, and norepinephrine-3-sulfate: determination of the position of the sulfate group by 1H-NMR spectroscopy.

Abstract

With respect to the growing interest in sulfoconjugated catecholamines (CAS), reliable syntheses of those substances including high purification and unequivocal identification are required. For the syntheses of the 3-O-sulfates of norepinephrine (NE) and epinephrine (EPI), modifications of the methods of Stolz (12) and Arakawa et al. (1) were performed. Noradrenalone and adrenalone were prepared according to the method of Stolz (12) and sulfated by reaction with pyridine-sulfurtrioxide complex in dry pyridine at 60 degrees C. After reduction of these ketosulfates by sodium borohydride in dry pyridine, NE-3-O-S and EPI-3-O-S were obtained respectively. We synthesized dopamine-4-O-sulfate (DA-4-O-S) by reaction of DA hydrochloride with pyridine-sulfurtrioxide complex in dry dimethylformamide at 20 degrees C (Harbeson et al., 1983). The highly purified products (DA-4-O-S, NE-3-O-S, EPI-3-O-S) were characterized by their melting points (mp), infrared spectra (IR), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), elemental analysis, and 1H-nuclear magnetic resonance spectroscopy (1H-NMR).