3-Nitroatenolol: First Synthesis, Chiral Resolution and Enantiomers’ Absolute Configuration

Abstract

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.

Bioactive Alkaloids from the Mangrove-Derived Fungus Nigrospora oryzae SYSU-MS0024

“…The absolute configuration of 1 was assigned as (5R,1′R) by a single-crystal X-ray diffraction experiment using Cu-Kα radiation [16] were observed in the same CDCl3 solvent, which suggested that 2 could be a 5-epimer of 1 (Table 1). The absolute configuration of the secondary hydroxylated carbon (C-1′) was determined using a modified Mosher's method [17][18][19][20]. The chemical shifts for H-2′, H-4, and H-7 of 1a and 1b were measured as δH 1.49, 4.94, 2.38 for 1a, and δH 1.44, 4.96, 2.49 for 1b, respectively.…”

“…Compound 2 shared the same planar structure as 1 and was further identified by 2D NMR spectra, including 1 1). The absolute configuration of the secondary hydroxylated carbon (C-1′) wa determined using a modified Mosher's method [17][18][19][20]. The chemical shifts for H-2′, H-4 and H-7 of 1a and 1b were measured as δH 1.49, 4.94, 2.38 for 1a, and δH 1.44, 4.96, 2.49 fo 1b, respectively.…”

“…The minor chemical shift variation in C-4 (δC 25.6, δH 2.62, 1.98 for 1; δC 25.5, δH 2.68, 1.93 for 2), C-5 (δC 93.6 for 1; δC 94.0 for 2), C-1′ (δC 65.4, δH 4.22 for 1; δC 65.8, δH 4.19 for 2), and C-2′ (δC 16.3, δH 1.13 for 1; δC 16.3, δH 1.31 for 2)were observed in the same CDCl3 solvent, which suggested that 2 could be a 5-epimer of 1 (Table1). The absolute configuration of the secondary hydroxylated carbon (C-1′) was determined using a modified Mosher's method[17][18][19][20]. The chemical shifts for H-2′, H-4, and H-7 of 1a and 1b were measured as δH 1.49, 4.94, 2.38 for 1a, and δH 1.44, 4.96, 2.49 for 1b, respectively.…”