Pyridine → HCID 14824298, compound

Participants

Reaction Steps

To a stirred solution of N-benzyloxycarbonyl-L-valine (0.50 g, 2.00 mmol) and pyridine (0.16 ml, 2.00 mmol) in anhydrous DCM (5 ml) kept under a N2 atmosphere was added cyanuric fluoride (0.90 ml, 10.00 mmol) at −15 to −10° C. A white precipitate formed. The reaction was followed by TLC CHCl3/MeOH/AcOH (9:1:0.1) on a small amount of reaction mixture quenched in MeOH. After 1 hr 40 min, crushed ice was added along with DCM (10 ml). The organic layer was separated and the aqueous layer extracted with DCM (5 ml). The combined DCM layers were washed with ice-cold water (10 ml), dried (MgSO4) and concentrated under reduced pressure to afford a colourless oil (0.60 g, 119%) which was used in subsequent reactions without further purification: Rf=0.78 CHCl3/MeOH/AcOH (9:1:0.1); νmax(polyethylene card) 3320 (N—H), 1843 (acid fluoride), 1738 (urethane, C═O), 1538 (amide II); δH (200 MHz, CDCl3) 1.01 (3H, d, J 7.0, CH(CAH3CBH3)), 1.05 (3H, d, J 7.0, CH(CAH3CBH3)), 2.26 (1H, m, CH(CH3)2), 4.49 (1H, m, NHCH), 5.14 (3H, m, OCH2Ph & NH (masked)), 7.37 (5H, s, Ar—H); MS ES (+ve) found m/z 233.8 (C6H5CH2CONHCH(CH(CH3)2)CO—, 41%), 251.8 (N-Cbz-Val, 58), 268.9 (N-Cbz-ValNH4+, 64), 273.8 (N-Cbz-ValNa+, 33), 289.9 (N-Cbz-ValK+, 22), 341.9 (100), 502.1 (N-Cbz-Val dimer, 53), 507.1 (M+ dimer, 55).

Provenance & Evidence