Oxalic Acid → HCID 20042478, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(4-methylbenzyl)piperazine (9.5 g) in tetrahydrofuran (50 cc) is added in the course of 10 minutes at a temperature in the region of 20° C. to a stirred solution of 3-phenyl-3-pyrazinylpropenal (1 g) in tetrahydrofuran (50 cc), and the mixture is left with stirring for 3 hours at a temperature in the region of 66° C. After the solution is cooled to a temperature in the region of 20° C., the reaction mixture is concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C. A residue is obtained which is dissolved in methylene chloride (10 cc). The solution obtained is poured onto silica (200 g) contained in a column 3.5 cm in diameter. Elution is performed with a mixture (500 cc) of methylene chloride and methanol (99.5:0.5 by volume) and the corresponding eluate is evaporated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C. The oil obtained is dissolved in boiling methyl ethyl ketone (20 cc). A solution of oxalic acid (0.25 g) in boiling methyl ethyl ketone (20 cc) is added. After the mixture is cooled to a temperature in the region of 20° C., the precipitate formed is separated by filtration and then recrystallized in boiling isopropyl alcohol (80 cc). 3-[4-(4-Methylbenzyl)-1-piperazinyl]-1-phenylpyrrolo[1,2-a]pyrazine oxalate (0.4 g), m.p. 128° C., is thereby obtained.

Provenance & Evidence