Trifluoroacetic acid → 1,2-Dimethyl-4-(3,4,5-trimethoxyphenyl)-7-methoxy-1,4-dihydro-3(2H)-isoquinolinone
Reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:13](OC(=O)C)[C:14]([N:16]([CH3:27])[CH:17]([C:19]2[CH:24]=[CH:23][CH:22]=[C:21]([O:25][CH3:26])[CH:20]=2)[CH3:18])=[O:15])[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[O:9][CH3:10].FC(F)(F)C(O)=O>ClCCl>[CH3:18][CH:17]1[C:19]2[C:24](=[CH:23][CH:22]=[C:21]([O:25][CH3:26])[CH:20]=2)[CH:13]([C:5]2[CH:6]=[C:7]([O:11][CH3:12])[C:8]([O:9][CH3:10])=[C:3]([O:2][CH3:1])[CH:4]=2)[C:14](=[O:15])[N:16]1[CH3:27]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of the amide from step 2 above (4.2 g) in dichloromethane (60 ml) and trifluoroacetic acid (20 ml) was refluxed for 4 hours. The reaction mixture was concentrated to dryness and the residue was submitted to chromatography on silica gel using dichloromethane-ethyl acetate (6:4) as eluent. The first fraction was concentrated to dryness and the residue was crystallized from methanol giving diastereomer I, m.p. 135-140° C. The third fraction contained diastereomer II, which was recovered as an amorphous solid.