Dichloromethane → Hydrochloric Acid
Reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:13]=[CH:14][C:15]=1[C:16]([CH3:22])([CH3:21])[C:17]([O:19][CH3:20])=[O:18])[C:6]([O:8]C(C)(C)C)=[O:7].C(O)(C(F)(F)F)=O.C(Cl)[Cl:31]>>[ClH:31].[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:13]=[CH:14][C:15]=1[C:16]([CH3:22])([CH3:21])[C:17]([O:19][CH3:20])=[O:18])[C:6]([OH:8])=[O:7]Participants
5
Procedure
To the crude tert-butyl 3-methoxy-4-(1-methoxy-2-methyl-1-oxopropan-2-yl)benzoate from Step 2 was added DCM (1 mL) followed by TFA (540 μL, 7.0 mmol). The reaction was allowed to stir for 2 h before it was concentrated in vacuo. The residue was dissolved in DMF, filtered and was purified by prep-HPLC (MeOH:H2O, 1-99% in an HCl modifier) to give 3-methoxy-4-(1-methoxy-2-methyl-1-oxopropan-2-yl)benzoic acid. ESI-MS m/z calc. 252.1. found 253.2 (M+1)+; Retention time: 2.45 minutes (4 min run).