Benzophenone imine → 6-Amino-1-isopropyl-4,4,7-trimethyl-2-oxo-1,2,3,4-tetrahydroquinoline

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Reaction Conditions

Reaction Steps

A solution of 6-bromo-1-isopropyl-4,4,7-trimethyl-2-oxo-1,2,3,4-tetrahydroquinoline (Compound 17, 2.86 g, 9.2 mmol), benzophenone imine (1.54 g, 8.5 mmol) in 25.0 mL of toluene was degassed with argon for 20 minutes. To this solution was added sodium t-butoxide (1.16 g, 1.2 mmol), tris(dibenzylideneacetone)dipalladium(0) (97 mg, 0.11 mmol) and BINAP (0.18 g, 0.29 mmol) consecutively. The reaction mixture was then heated at 80° C. for 24 hours. Thereafter it was cooled to room temperature, diluted with ether, filtered and concentrated. The residue was diluted with tetrahydrofuran (10.0 mL) and and 10% aqueous HCl and stirred for 1 hour. 0.5 M HCl and 30% hexane in ethyl acetate were then added. The layers were separated and the aqueous layer was made alkaline using saturated NaHCO3 and water. The aqueous layer was extracted with methylene chloride (2×). The combined organic extracts were washed with brine and dried (Na2SO4). The filtered solution was concentrated under reduced pressure and the crude product was purified by silica gel chromatography (30% ethyl acetate in hexanes) to give the title compound (0.63 g, 56%) as a solid.

Provenance & Evidence