GENERAL STEPS: To a stirred mixture of 1-adamantanecarboxylic acid (11, 36.05 g, 200 mmol) and DMF (5 drops) in CH2Cl2 (360 mL) was added thionyl chloride (26.17 g, 220 mmol) in batches under cooling conditions in an ice-water bath. The resulting mixture was refluxed until the release of HCl gas ceased (usually takes 2 hours). Subsequently, the solvent and excess thionyl chloride were removed using a rotary evaporator and the crude product, adamantanoyl chloride (12), was dissolved in THF (100 mL). This solution was slowly added dropwise to concentrated ammonia (400 mL) cooled and stirred in an ice water bath. After the dropwise addition was completed, the white slurry formed was continued to be stirred at room temperature for 2 hours. The white precipitate was collected by vacuum filtration, washed with cold hexane, and dried under vacuum to give 1-adamantanecarboxamide (13). The product was a white solid with a yield of 34.06 g (95% yield) and a melting point of 177-179 °C (literature value: 185.5-191.7 °C [48]).1H-NMR (DMSO-d6, 400 MHz) δ: 6.89 (brs, 1H), 6.62 (brs, 1H), 1.93 (s, 3H), 1.73-1.74 (m , 6H), 1.60-1.68 (m, 6H).
