Thioglycolic Acid → 5-(3,5-Dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)-2-methylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

2-(3-Carboxy-4-methyl-phenyl)-3,5-dioxo-2,3,4,5-tetrahydro-[1,2,4]triazine-6-carboxylic acid (110 gm) was added to 8 volumes of water with 2.4 equivalents of sodium hydroxide and 1.1 equivalents of mercaptoacetic acid. The reaction mixture was heated to reflux (100-105° C.) for approximately 18 hours at which point the reaction was complete by HPLC. 30% Sodium hydroxide and toluene were added and the resulting mixture was stirred. Upon settling a large interface was noted. More water, toluene and some ethyl acetate were added. The interface was minimized. The water layer was separated and treated with 2N HCl. At pH 2 solids precipitated out and the slurry was cooled to <10° C. The solids were filtered off in a slow filtration and dried in a vacuum oven to give 69 gm of the title compound.

Provenance & Evidence