Oxalic Acid → HCID 20065667, compound

Participants

Reaction Steps

A solution of 2-[3-(4-phenyl-1,2,3,6-tetrahydro-1pyridyl)propyl]-3-hydroxy-1-isoindolinone (5.2 g) in anhydrous dimethyl formamide (50 cc) is added to a suspension of sodium hydride (as a 50% suspension in oil, 0.8 g) in anhydrous dimethylformamide (10 cc) at a temperature close to 20° C. in the course of 15 minutes, and agitation is continued for 2 hours. Then, 1 cc of methyl iodide is added in the course of 5 minutes and agitation is continued for a further 20 hours. The suspension obtained is poured into distilled water (1000 cc) and extracted with methylene chloride (3×1000 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 (20 cc) and the solution poured onto silica (300 g) contained in a column of 7 cm diameter. Elution is carried out with a mixture of methylene chloride and methanol (98-2 by volume, 1 liter) and the corresponding eluate evaporated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 50° C. The residue obtained is dissolved in methyl ethyl ketone (30 cc). A solution of oxalic acid (0.7 g) in methyl ethyl ketone (10 cc) is added and agitation is continued for 1 hour at a temperature close to 20° C. The precipitate formed is separated by filtration. 2.6 g of 3-methoxy-2-[3-(4-phenyl-1,2,3,6-tetrahydro-1-pyridyl)propyl]-1-isoindolinone oxalate are thus obtained, melting at 160° C.

Provenance & Evidence