Methanesulfonic Acid → Tilomisole

Participants

Reaction Steps

A mixture of 100 g of 3-(p-Chlorophenyl)-2,3,-dihydro-3-hydroxythiazolo[3,2-a]benzimidazol-2-acetic acid, hydrobromide and 200 ml of methanesulphonic acid was stirred overnight in a 500 ml round bottom flask. Thin layer chromatography on silica plates (solvent ethyl acetate/acetic acid) indicated rapid formation of an intermediate. After 20 hours at room temperature thin layer chromatography (silica plates, ethyl acetate/acetic acid) showed the presence of a single component. The mixture was poured into water and the resulting crystals removed by filtration. The crystalline product was suspended in 5 volumes of hot water for 1/2 hour, filtered and the procedure repeated. After a final aqueous wash the material was dried in vacuo to yield the title compound (75 g, 91%) m.p. 242°-3° C.

Provenance & Evidence