An improved synthesis of an umbelliferyl 5-thioxylopyranoside, precursor of the antithrombotic drug Iliparcil.
4-Ethyl-2-oxo-2H-1-benzopyran-7-yl 2,3,4-tri-O-acetyl-5-thio-beta-D-xylopyranoside, a synthetic intermediate of the orally active antithrombotic compound Iliparcil, has been prepared in 44-47% isolated yield. Different conditions were used for the glycosylation of 4-ethyl-2H-7-hydroxy-1-benzopyran-2-one 6 applying 2,3,4-tri-O-acetyl-5-thio-D-xylopyranosyl bromide (2), the analogous beta-chloride 3 or the alpha-trichloroacetimidate 5 as donors. With halides 2 and 3, the reaction was carried out in the presence of ZnO-ZnCl2 or ZnO alone. Both promoters are cheap, safe and therefore compatible with large-scale industrial processes.
Collette
Y
Y
Laboratoires Fournier, Daix, France.
Ou
K
K
Pires
J
J
Baudry
M
M
Descotes
G
G
Praly
J P
JP
Barberousse
V
V
D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D005343:Fibrinolytic Agents / Q000138:chemical synthesis* / Q000737:chemistry; D007202:Indicators and Reagents; D015394:Molecular Structure; D009904:Optical Rotation
C122025:4-ethyl-2-oxo-2H-1-benzopyran-7-yl 2,3,4-tri-O-acetyl-5-thioxylopyranoside; D001578:Benzopyrans; D003374:Coumarins; D005343:Fibrinolytic Agents; D007202:Indicators and Reagents; C122024:iliparcil