Acetic Acid → 5-((5-(2-Methoxy-6-((4-methoxybenzyl)oxy)phenyl)-1H-pyrazol-3-yl)amino)pyrazine-2-carbonitrile

Participants

Reaction Conditions

Reaction Steps

In a 20 L container are combined ethanol (11.28 L) and acetic acid (318 mL, 5.545 mol). The reaction is vented to a bleach scrubber with a nitrogen purge. (E)-5-(3-(2-Methoxy-6-(4-methoxybenzyloxy)phenyl)-1-(methylthio)-3-oxoprop-1-enylamino)pyrazine-2-carbonitrile (940 g, 1.931 mol) and the ethanol/acetic acid solution are added to a 22 L reaction flask. To the resulting brown slurry is added hydrazine monohydrate (197 g, 3.935 mol), resulting in a slight exotherm. The resulting yellow slurry is slowly heated to 65-70° C. and monitored by HPLC. The duration of the reaction is less than one hour. The thick slurry is slowly cooled over 1-2 h to less than 30° C. The slurry is filtered and washed with cold ethanol. The material is vacuum dried at 40° C. affording (820 g, 99.1%) of the title compound. mp 215-117° C.; ES/MS m/z 429.2 [M+1]+.

Provenance & Evidence