Isobutylamine → Methyl 5-(benzyloxy)-2-isobutyl-1-oxo-1,2,3,4-tetrahydroisoquinoline-7-carboxylate

Participants

Reaction Steps

To a solution of dimethyl 5-(benzyloxy)-4-(2-oxoethyl)isophthalate (1.5 g, 4.38 mmol) in MeOH was added isobutylamine (385 mg, 0.522 mL, 5.26 mmol). The reaction was stirred at room temperature for 2 hrs, then NaCNBH3 (84.1 mg, 1.34 mmol) was added. The mixture was stirred at 75° C. overnight. The solvents were removed under reduced pressure, diluted with ethyl acetate and washed with brine (3×). The product was purified via gradient silica gel chromatography using MeOH/CHCl3 (5/95 to 10/90) to provide the product (1.1 g, 50% yield) as a film 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 0.96 (dd, 6H) 1.96-2.16 (m, 1 H) 3.05 (t, J=6.69 Hz, 2 H) 3.36-3.46 (m, J=7.63, 7.63 Hz, 2 H) 3.49-3.62 (m, 2 H) 3.88-4.02 (m, 3 H) 5.16 (s, 2 H) 7.32-7.56 (m, 5 H) 7.74 (d, J=1.32 Hz, 1 H) 8.42 (d, J=1.32 Hz, 1 H); MS (ESI, pos): 368.

Provenance & Evidence