[CH:1]([C:4]1[CH:10]=[CH:9][CH:8]=[C:7]([CH:11]([CH3:13])[CH3:12])[C:5]=1[NH2:6])([CH3:3])[CH3:2].[CH3:14][CH:15]([CH:17]=O)[CH3:16].C1(C)C=CC(S(O)(=O)=O)=CC=1.[O-]S([O-])(=O)=O.[Mg+2]>C(Cl)(Cl)Cl>[CH:11]([C:7]1[CH:8]=[CH:9][CH:10]=[C:4]([CH:1]([CH3:3])[CH3:2])[C:5]=1[N:6]=[CH:14][CH:15]([CH3:17])[CH3:16])([CH3:13])[CH3:12]2,6-Diisopropylaniline (9.4 mL, 50 mmol, Aldrich) was mixed with isobutyric aldehyde (9.1 mL, 100 mmol, Aldrich), p-toluenesulfonic acid (0.48 g, 2.5 mmol, Aldrich), chloroform (50 mL) and MgSO4 (12 g, 100 mmol). The mixture was stirred for 2 h at RT. Assay by 1H-NMR (crude reaction mixture) showed the presence of product and starting material (8/1 ratio). The reaction mixture was filtered, the precipitate washed with chloroform (50 mL), and 5 Å molecular sieves were added. After stirring for 20 h at RT the solution was filtered, the molecular sieves were washed with chloroform (2×50 mL), the solvent was evaporated, and the residue distilled at reduced pressure. After a few drops of forerun (67–76° C./27 Pa) product was collected at 76–77° C./27 Pa as a colorless oil, 8.66 g (74.8%). 1H NMR (CDCl3) 7.60 (d, 1H; J=4.8 Hz); 7.20–7.05 (m, 3H); 3.00 (septet, 2H; J=6.8 Hz); 2.78 (d of septets, 1H; J=4.8; 6.7 Hz); 1.33 (d, 6H; J=6.7 Hz); 1.23 (d, 12H; J=6.8 Hz).
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