Reaction Steps
A mixture of 3-(4-chlorobenzoyl) propionic acid (34) (2.50 g, 12.0 mmol), KOH (s) (1.75 g, 31.2 mmol), and hydrazine monohydrate (1.25 mL, 25.8 mmol) in 12.5 mL of diethylene glycol was refluxed azeotropically at 120-130° C. for 90 min to remove water. The reaction mixture was then refluxed at 170° C. for 3 h, cooled to RT, diluted with 12.5 mL of water, and poured into 15 mL 2.5 N HCl(aq). The precipate was filtered off, dissolved in CH2Cl2, and the solvent removed to give 35a (2.23 g, 96%) as a white solid. UV λmax 223 (8980, 95% ETHANOL); 1H NMR (400 MHz, CDCl3) δ 7.26 (d, J=7 Hz, 2H), 7.12 (d, J=8 Hz, 2H), 2.66 (t, J=4 Hz, 2H), 2.38 (t, J=4 Hz, 2H), 1.96 (m, 2H); 13C NMR (CDCl3) δ 179.3, 140.0, 132.2, 130.2, 128.9, 34.7, 33.4, 26.4; IR (drift) 3063 (s), 3051 (s), 2955 (s), 2923 (s,b), 2905 (s), 2814, 2797, 2493 (b), 2466, 2413, 2367 (b), 2321, 1706 (s), 1492 (s), 1212 (s), cm−1; MS (EI) m/z (rel. intensity) 198 (M+, 22), 200 (7), 198 (22), 140 (32), 139 (17), 138 (99), 127 (15), 125 (48), 103 (10), 89 (13), 60 (9); HRMS (EI) calcd for 198.0448, found 198.0441.
