Trifluoroacetic acid → 7-[4-Nitro-3-(propan-2-yloxy)phenyl]-1,7-diazaspiro[4.4]nonane

Participants

Reaction Steps

0.33 ml of trifluoroacetic acid is added to a solution of 300 mg of 2-methylpropan-2-yl 7-[4-nitro-3-(propan-2-yloxy)phenyl]-1,7-diazaspiro[4.4]nonane-1-carboxylate in 30 ml of dichloromethane. The mixture is stirred at ambient temperature for 15 hours and then 3 ml of trifluoroacetic acid are again added. After stirring for 15 hours, the reaction mixture is run into 50 ml of a saturated potassium carbonate solution. The aqueous phase is extracted three times with 50 ml of dichloromethane. The organic phases are combined, dried over anhydrous magnesium sulfate, filtered and then concentrated to dryness under reduced pressure, so as to give a yellow oil. The residue is purified by chromatography on silica gel, elution being carried out with dichloromethane/methanol (100/0 to 95/5), so as to obtain 221 mg of 7-[4-nitro-3-(propan-2-yloxy)phenyl]-1,7-diazaspiro[4.4]nonane in the form of a yellow solid.

Provenance & Evidence