Hydrochloric Acid → HCID 178488026, compound

Participants

Reaction Conditions

Reaction Steps

In a 50 L flask equipped with a mechanical stirrer, thermocouple and condenser was added 4-methoxy-1,2-phenylenediamine dihydrochloride salt (Compound 9) (2.65 kg @ 98 wt %, 12.30 mol), oxalic acid (1.582 kg @ 98 wt. %, 17.22 mol) and 3 N HCl(aq) (17.8 L) under nitrogen. The grey heterogeneous slurry was heated to 90° C. with steam for 7.25 hours. The reaction was monitored by HPLC. The resulting grey slurry was then cooled to an internal temperature of 20° C. overnight. The slurry was filtered, water (1.0-1.5 L/Kg) was used to help with the transfer. The light grey solids were washed with 2 cake volumes water (5.0-5.5 L/Kg). The solids were dried under vacuum/N2 sweep for 24 hours, at which time the solids were still very wet. The product was then slurry washed with methanol, and dried over 48 hours at 40-45° C. in a vacuum oven to give Compound 10 as an off-white product of 99.95% purity by HPLC assay. There was no methanol by NMR and the KF=0.05 wt. % water.

Provenance & Evidence