To a first solution of hydroxylamine hydrochloride (66 mg, 0.950 mmol) and phenolphthalein (0.5 mg) in methanol (3 mL), was added dropwise a second solution of sodium metal (33 mg, 1.435 mmol) in methanol (3 mL) via additional funnel until a pink endpoint was reached and precipitate appeared. To the reaction mixture was added a solution of 7-(adamantan-1-yl-carbamoyl)-heptanoic acid methyl ester (152 mg, 0.474 mmol) in methanol (4 mL) was added, followed by the remainder of the second solution of sodium metal in methanol. The resulting reaction was allowed to stir for 24 hours, then the reaction mixture was diluted with water (15 mL), followed by glacial acetic acid (0.2 mL) with stirring. The resulting precipitate was suction filtered and rinsed using water, then dried at room temperature under vacuum to provide a crude residue which was purified by recrystallization from dichloromethane/hexane to provide Compound 17 (104 mg, 68% yield). 1H NMR (300 MHz, CD3OD) δ 7.31 (br s, 1H), 2.09 (t, J=7.5 Hz, 2H), 2.08-1.98 (m, 11H), 1.71 (m, 6H), 1.59 (m, 4H), 1.33 (m, 4H). 13C NMR (75 MHz, CD3OD) δ 175.7, 173.1, 52.8, 42.5, 38.0, 37.7, 33.9, 31.1, 30.00, 29.96, 27.2, 26.8.
