Hydrochloric Acid → HCID 178435256, compound

Participants

Reaction Conditions

Reaction Steps

4-(2-ethyl-2,3-dihydro-1-hydroxy-1H-inden-2-yl)-1H-imidazole (5 kg), water (40 kg), 30% HCl (34 kg), ethanol (22 kg) and 10% palladium on charcoal (0.5 kg) are charged. The mixture is stirred under 2.2 bar overpressure of hydrogen at 80±3° C. for 12 hours. The reaction mixture is filtered at 73±2° C., the filter cake is washed with water (7 kg) and the filtrates are combined. The reaction mixture is heated to boil and 50 l of the solvent is distilled off. The solution is cooled to 0±2° C. during 2 h. The solution is seeded during the cooling procedure with atipamezole HCl at 100±5° C., 90±5° C., 80±5° C. and at 70±5° C., until the crystallization starts. The mixture is agitated for two hours at 0±2° C. The crystalline compound is recovered by centrifugation and washed with HCl-water mixture (0.34 kg HCl and 10 kg of water) and then with 18 kg of acetone. The product is dried under reduced pressure raising the temperature gradually to 85±3° C. The yield is 4.8 kg (89%).

Provenance & Evidence