1: 1.) trifluoroacetic acid, 2.) aq. sodium hydroxide / 1.) benzene, 5 min, 2.) diethyl ether, 2 min 2: 1.) aq. sodium hydroxide / 1.) 20 deg C, 2 d, 2.) acetone, reflux, 6 h 3: 1.) trifluoroacetic anhydride, pyridine, 2.) trifluoroacetic acid / 1.) methylene dichloride, 1 h, 2.) 20 deg C, 5 min 4: 65 percent / aq. sodium hydroxide / ethanol / 5 h / Heating View Scheme

1: 1.) trifluoroacetic acid, 2.) aq. sodium hydroxide / 1.) benzene, 5 min, 2.) diethyl ether, 2 min 2: 1.) aq. sodium hydroxide / 1.) 20 deg C, 2 d, 2.) acetone, reflux, 6 h 3: 1.) trifluoroacetic anhydride, pyridine, 2.) trifluoroacetic acid / 1.) methylene dichloride, 1 h, 2.) 20 deg C, 5 min View Scheme

1: 1.) trifluoroacetic acid, 2.) aq. sodium hydroxide / 1.) benzene, 5 min, 2.) diethyl ether, 2 min 2: 1.) aq. sodium hydroxide / 1.) 20 deg C, 2 d, 2.) acetone, reflux, 6 h 3: trifluoroacetic anhydride, pyridine / CH2Cl2 / 1 h View Scheme