Sodium triacetoxyborohydride → tert-Butyl 2,2-dimethyl-5-((5-(5-(4-propylphenyl)-1,2,4-oxadiazol-3-yl)-3,4-dihydroquinolin-1(2H)-yl)methyl)-1,3-dioxan-5-ylcarbamate

Participants

Reaction Steps

To a mixture of the product of Step D (0.0334 g; 0.1 mmol), tert-butyl 5-formyl-2,2-dimethyl-1,3-dioxan-5-ylcarbamate (3×0.03 g; 0.33 mmol) and NaBH(OAc)3 (3×0.07 g; 0.93 mmol) in 1,2-dichloroethane (1.5 ml) AcOH (3×0.01 ml) was added portion wise over a period of 3 days with stirring at room temperature. The mixture was then diluted to 15 ml with EtOAc, washed with 10% NaOH, H2O, brine, dried over anhydrous MgSO4, filtered and filtrate evaporated to dryness under reduced pressure. The residue was purified by FCC (SiO2, hexane:EtOAc, 9:1), to give the title compound (0.03 g; 51%) as colourless foam. 1H-NMR (CDCl3) 0.95 (tr, 3H, J=7.4 Hz); 1.44 (m, 15H); 1.61-1.72 (m, 2H); 1.89-1.97 (m, 2H); 2.66 (tr, 2H, J=7.8 Hz); 3.06 (tr, 2H; J=6.5 Hz); 3.34 (tr, 2H, J=5.4 Hz); 3.77 (s, 2H); 3.95 (s, 4H); 4.7 (broad s, 1H); 7.02 (d, 1H, J=7.6 Hz); 7.14 (tr, 1H, J=7.6 Hz); 7.22-7.25 (m, 1H+CDCl3); 7.33 (d, 2H, J=8.3 Hz); 8.09 (d, 2H, J=8.3 Hz).

Provenance & Evidence