Characterization of PZQ-enamide

Published by Ahamed on 25 August 2010 - 5:32am

The PZQ-enamide is shown below. This is an intermediate in the stereoablative route to enantiopure PZQ.

HPLC trace for PZQ-enamide (using ChiralcelOD-H, solvents: Hex:IPA:TEA 60:40:0.1, Flow Rate: 0.7 mL/min) gives retention time: 15.772 mins. Original HPLC trace attached below.
 
(Note comparison HPLC trace for PZQ itself is here.)
 
Other data: RF =0.35(1:1 Hexane: EtOAc); m.p. 131-134 ºC; 1H NMR (300 MHz, CDCl3): δ 1.15-1.85 (10H, m, cy), 2.35-2.65 (1H, m, cy ), 2.84 (t, 2H, J 5.2, H7), 3.82 (t, 2H, J 5.5, H6), 4.35 (1H, s, H4), 6.70 (1H, s, H2), 7.10-7.51 (4H, m, Ar); (Proton NMR spectrum attached below) 13C NMR (75 MHz, CDCl3): δ 26.1, 29.4, 38.8, 41.4, 45.9, 48.7, 106.0, 106.0, 123.1, 123.6, 126.9, 127.7, 128.2, 128.4, 128.6, 128.8, 129.0, 134.5, 164.3, 174.5; IR (CHCl3): 2952-2870 cm-1, 1652 cm-1, 1463 cm-1; MS (ESI) m/z: 311.1 [(MH)+, 100%], 333.3 [(MNa)+, 55%] HRMS (ESI) Calcd. for C19H22N2NaO2 (MNa+): 333.15735. Found: 333.15765.