Reaktion #331415

Reaktionsgleichung

[3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclobutyl]methanol

cyclooctane-1,5-diol

p-toluenesulfonic anhydride

i-Pr2NEt

→

cis-3-(8-Chloroimidazo[1,5-a]pyrazin-3-yl)cyclobutylmethyl toluene-4-sulfonate

trans-3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclobutylmethyl toluene-4-sulfonate

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeSolvents were removed
2. 2
   Sonstigethe residue was purified by silica gel chromatography (hexanes/EtOAc:4/1 to 1/1)
3. 3
   Sonstigeto afford the respective cis- and trans-title compounds

Vorschrift

cis-3-(8-Chloroimidazo[1,5-a]pyrazin-3-yl)cyclobutylmethyl toluene-4-sulfonate and trans-3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclobutylmethyl toluene-4-sulfonate were prepared as follows: To a solution of [3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclobutyl]methanol (˜5:1 mixture of cis- and trans-isomers, contaminated with unknown amount of cyclooctane-1,5-diol from the previous reaction, 118.8 mg, 0.5 mmol) and p-toluenesulfonic anhydride (244.8 mg, 0.75 mmol) in dichloromethane (2.0 mL) was added i-Pr2NEt (0.26 mL, 1.5 mmol). The resulting mixture was stirred at rt for 15 h. Solvents were removed and the residue was purified by silica gel chromatography (hexanes/EtOAc:4/1 to 1/1) to afford the respective cis- and trans-title compounds:

Quelle