Sodium Thiosulfate → UK-333747

Participants

Reaction Steps

(−)-6,7-Dichloro-5-[3-methoxymethyl-5-(3-pyridyl)-4H-1,2,4-triazol-4-yl]-2,3(1H,4H)-quinoxalinedione (see Preparation 1) (412.2 g, 0.98 mol) and OXONE (trade mark) (1.44 kg, 2.3 mol) were slurried in water (4.13 L) and the mixture stirred at ambient temperature for 60 hours. Saturated aqueous sodium thiosulphate solution (2.2 L) was added and the slurry stirred for 1 hour before being filtered under reduced pressure. The filter cake was slurried at ambient temperature for 4 hours in 1:1, by volume, isopropyl alcohol: dichloromethane (111 L) and the solid collected by filtration. The filtrate was vaporated under reduced pressure to give the title compound as a colourless solid (366 g).

Provenance & Evidence