Hydrochloric Acid → HCID 67225432, compound

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Reaction Steps

300 mg 1-Dimethylamino-4-[2-(2,4,6-trimethyl-phenyl)-acetylamino]-piperidine-4-carboxylic acid methyl ester (from Step 3) is dissolved in 5 ml N,N-dimethylformamide, and 466 mg potassium t-butoxide is added. The mixture is stirred at room temperature for 18 hours. Then water is added, and the pH adjusted to 5.2 by the addition of aqueous hydrochloric acid. The mixture is extracted with ethyl acetate, the organic layer washed with brine, dried over sodium sulfate, and the solvent evaporated. The residue is purified by chromatography on silica gel, with toluene/ethanol/dioxane/triethylamine/water (20:8:4:4:1) as a solvent. Thus, 196 mg 8-Dimethylamino-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]decane-2,4-dione is obtained as a solid, mp 237-241° C. 1H-NMR (d4-methanol): 6.94 ppm (s, 2H), 3.09 ppm (m, 2H), 2.79 ppm (m, 2H), 2.53 ppm (s, 6H), 2.28 ppm (m, 5H), 2.16 ppm (s, 6H), 1.64 ppm (m, 2H).

Provenance & Evidence