Oxalic Acid → HCID 20065665, compound

Participants

Reaction Steps

A solution of 3-dimethylamino-1-isoindolinone (11.7 g) in anhydrous dimethylformamide (300 cc) is added to a suspension of sodium hydride (as a 50% suspension in oil) (3.5 g) in anhydrous dimethylformamide (150 cc) at a temperature close to 20° C. in the course of 30 minutes, and agitation is continued for 1 hour. Then, a solution of 3-(4-phenyl-1,2,3,6-tetrahydro-1-pyridyl)-1-bromopropane (20.5 g) in dimethylformamide (150 cc) is added in the course of 15 minutes, and agitation is continued for a further 20 hours. The solution obtained is evaporated to dryness under reduced pressure (1 mm mercury; 0.1 kPa). The residue obtained is dissolved in methylene chloride (350 cc) and washed with distilled water (3×150 cc). The organic extract is 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 (50 cc) and poured onto silica (1000 g) contained in a column of 8 cm diameter. Elution is carried out with a mixture of methylene chloride and methanol (95-5 by volume). The first 2300 cc are eliminated and the eluate corresponding to the next 1500 cc is concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa). The residue obtained is dissolved in methyl ethyl ketone (80 cc). A solution of oxalic acid (1.9 g) in methyl ethyl ketone (20 cc) is added and agitation is continued for 1 hour at a temperature close to 20° C. The precipitate formed is separated by filtration. 7.6 g of 3-dimethylamino-2-[3-(4-phenyl-1,2,3,6-tetrahydro-1-pyridyl)propyl]-1-isoindolinone oxalate are thus obtained, melting at 159° C.

Provenance & Evidence