Ammonia → HCID 20065651, compound

Participants

Reaction Steps

28.5 cc of concentrated sulphuric acid is added to an agitated solution of 2-[3-(4-(4-fluorophenyl)-1,2,3,6-tetrahydro-1-pyridyl)propyl]-3-hydroxy-1-isoindolinone (5.7 g) in methanol (145 cc) at a temperature close to 20° C. in the course of 10 minutes. Agitation is continued for 5 hours at a temperature close to 65° C. After cooling the solution to a temperature close to 0° C., 70 cc of a 33% aqueous solution of ammonia is added in the course of 1 hour. The precipitate formed is filtered and washed with methanol (50 cc). The filtrate is diluted with distilled water (200 cc) and a 33% aqueous solution of ammonia (50 cc) and extracted with methylene chloride (3×200 cc). The organic extracts are combined, dried over anhydrous magnesium sulphate, filtered and concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C. The residue obtained is dissolved in methylene chloride (10 cc) and the solution poured onto silica (550 g) contained in a column of 8 cm diameter. Elution is carried out with a mixture of methylene chloride and methanol (90-10 by volume). The first 900 cc are eliminated and the following 200 cc are evaporated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 50° C. The residue obtained is dissolved in methyl ethyl ketone (10 cc). A solution of oxalic acid (0.6 g) in methyl ethyl ketone (5 cc) is added and agitation continued for 1 hour at a temperature close to 20° C. The precipitate formed is separated by filtration. 2.4 g of 3-methoxy-2-[3-(4-(4-fluorophenyl)-1,2,3,6-tetrahydro-1-pyridyl)propyl]-1-isoindolinone oxalate are obtained, melting at 139° C.

Provenance & Evidence