Fumaric Acid → HCID 19095372, compound

Participants

Reaction Steps

6-(3,4-Dimethoxyphenyl)-3,4-dihydro-1-methylpyrrolo[1,2-a]pyrazine (1.3 g) was dissolved in a mixture of 80 ml of methanol and 8 ml of water under argon. The solution was treated portionwise with 0.6 g of sodium borohydride while stirring and stirred at room temperature overnight. Thereafter, the methanol was removed in a vacuum, the residue was taken up in 100 ml of methylene chloride and washed with 100 ml of 10% ammonia solution. The phases were separated and the aqueous phase was extracted twice with 50 ml of methylene chloride each time. The organic phases were combined, dried with MgSO4 and freed from solvent. The crude product, 1.3 g of yellow-brown oil, was chromatographed on 60 g of silica gel with methylene chloride/methanol (49:1) as the eluent. The product, 0.9 g of yellow oil was dissolved in a 20-fold amount of ethanol, treated with 1.1 equivalents of a saturated solution of fumaric acid in ethanol, concentrated to 10 ml and treated with 40 ml of ethyl acetate. There was obtained 0.5 g (37%) of 6-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydro-1-methylpyrrolo[1,2-a]pyrazine fumarate (1:0.6); m.pt.: 172°-175° C. (dec.). A sample was recrystallized from a 40-fold amount of ethanol and yielded the (2:1) fumarate; m.pt.: 178°-180° C. (dec.).

Provenance & Evidence