Practical Syntheses of the Adhesion Molecule Inhibitor ER-49890 and Its Stereoisomer
摘要:
Practical synthetic routes to anti-[3-(10H-pyrazino[2,3 -b] [ 1,4]-benzothiazin-8 -ylmethyl)-3 -azabicyclo [3.3.1]non-9-yl]acetic acid (ER-49890, 1) and its syn-isomer are reported. The anti-(3-azabicyclo[3.3.1]non-9-yl)acetic acid side chain (anti-12) was synthesized stereoselectively using Pd/C hydrogenation in the presence of HCL The syn-isomer (syn-12) was concisely obtained by crystallization as its oxalic acid salt from a 1: 1 mixture of anti- and syn-isomers. The 10H-pyrazino[2,3-b][1,4]benzothiazine core (7) was prepared from commercially available 4-chloro-3-nitrobenzyl alcohol (13) in four steps and good yield.
Practical Syntheses of the Adhesion Molecule Inhibitor ER-49890 and Its Stereoisomer
作者:Toshihiko Kaneko、Fumihiro Ozaki、Richard S. J. Clark、Yuki Komatsu、Kazuo Okano
DOI:10.3987/com-04-10279
日期:——
Practical synthetic routes to anti-[3-(10H-pyrazino[2,3 -b] [ 1,4]-benzothiazin-8 -ylmethyl)-3 -azabicyclo [3.3.1]non-9-yl]acetic acid (ER-49890, 1) and its syn-isomer are reported. The anti-(3-azabicyclo[3.3.1]non-9-yl)acetic acid side chain (anti-12) was synthesized stereoselectively using Pd/C hydrogenation in the presence of HCL The syn-isomer (syn-12) was concisely obtained by crystallization as its oxalic acid salt from a 1: 1 mixture of anti- and syn-isomers. The 10H-pyrazino[2,3-b][1,4]benzothiazine core (7) was prepared from commercially available 4-chloro-3-nitrobenzyl alcohol (13) in four steps and good yield.