Glutaric anhydride → Methyl (r) 4-[1-(1,2,3,4-tetrahydro-quinolin-6-yl)-2-methoxycarbonyl-ethylcarbamoyl]-butyrate

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Reaction Steps

A stirred solution of methyl (R) 3-amino-3-(1-boc-1,2,3,4-tetrahydro-quinolin-6-yl)-propionate (1.7 g, Reference Example 14) in tetrahydrofuran (50 ml) was treated with glutaric anhydride. After stirring for 4 hours the mixture was evaporated to dryness the residue was dissolved in methanol (40 ml) and treated with conc. sulphuric acid (20 drops). This solution was stirred at reflux for 3 hours and then allowed to stand at room temperature overnight. After the addition of solid sodium bicarbonate (10 g) the mixture was evaporated to dryness and the residue was partitioned between ethyl acetate and aqueous sodium bicarbonate solution. The aqueous layer was extracted with fresh ethyl acetate. The combined organic layer and extracts were washed with brine, then dried and then evaporated. The residue was subjected to flash chromatography on silica eluting with ethyl acetate to give the title compound (1.6 g) as a yellow oil. MS (ES+) 363 (MH+), 385 (MNa+) MS (ES−) 361 (MH−).

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