Synthesis
Part A. 1-Phenyl-1-cyclobutanecarbonitrile (5.0 g, 31.83 mmol) and potassium hydroxide (85%, 6.29 g, 95.49 mmol, 3 eq.) were dissolved in ethylene glycol (10 mL) and the reaction was heated for 6 h at 185-190 °C under nitrogen protection. The completion of the reaction was monitored by LC-MS. The reaction mixture was cooled and diluted with the addition of water. The mixture was extracted with ether (3 x 10 mL). The aqueous layer was acidified with concentrated hydrochloric acid to pH < 2 and subsequently extracted with chloroform (2 x 10 mL). The chloroform layers were combined, washed sequentially with water and saturated saline, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give 1-phenyl-1-cyclobutanecarboxylic acid (4.43 g, yield 79.2%). lC-MS (ESI+) m/z: 177.4 [M+H]+, retention time tR = 2.56 min (mobile phase: 10-90% acetonitrile/water, run time 6 min) .
References
[1] Chemische Berichte, 1984, vol. 117, # 11, p. 3303 - 3319
[2] Journal of Medicinal Chemistry, 2015, vol. 58, # 18, p. 7341 - 7348
[3] Patent: WO2003/99276, 2003, A1. Location in patent: Page 316-317
[4] Journal of Organometallic Chemistry, 1993, vol. 448, # 1-2, p. 9 - 14
[5] Pharmaceutical Chemistry Journal, 1980, vol. 14, # 2, p. 114 - 118
