Hydrochloric Acid → 1-(1-(benzyloxycarbonyl)piperidin-3-yl)-2-oxo-5-phenyl-2,3-dihydro-1H-imidazole-4-carboxylic acid

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Reaction Conditions

Reaction Steps

(2.6 g, 5.78 mmol) prepared in the previous step was combined with 26 mL of dioxane and 29 mL of 1N LiOH. The mixture was heated at 55° C. overnight. After the disappearance of 16D as monitored by LC/MS, the reaction was cooled to RT and approximately 50 mL of 1N HCl was added directly. The aqueous mixture was extracted with ethyl acetate (3×40 mL), washed with brine, dried over MgSO4, and concentrated in vacuo to afford 1-(1-(benzyloxycarbonyl)piperidin-3-yl)-2-oxo-5-phenyl-2,3-dihydro-1H-imidazole-4-carboxylic acid as an oil (16E) (2.43 g, quantitative yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.13 (d, J=9.60 Hz, 1H) 1.25 (br. s., 1H) 1.61-1.77 (m, 2H) 2.60 (br. s., 1H) 3.25 (br. s., 1H) 3.84-4.00 (m, 2H) 4.99 (s, 2H) 7.27-7.47 (m, 10H) 7.92-7.97 (m, 1H) 10.79 (s, 1H) 12.43 (br. s., 1H). This was used in next step without purification. ESI-MS: m/z 422.3 (M+H)+.

Provenance & Evidence