Sodium Hydroxide → HCID 19095438, compound

Participants

Reaction Steps

N-[2-[2-(3,4-Dimethoxyphenyl)pyrrol-1-yl]-ethyl]-acetamide (2.6 g) was treated with 20 ml of phosphorus oxychloride under argon and boiled for 1 hour while stirring. The reaction mixture was hydrolyzed at 0° C. with 100 ml of 2N sodium hydroxide solution and 100 ml of 28% sodium hydroxide solution, diluted with 1200 ml of water and extracted with methylene chloride (1×200 ml, 2×100 ml). The organic extracts were combined, dried with MgSO4 and freed from solvent. 1.4 g of a total of 2.7 g of crude product were chromatographed on 30 g of silica gel with methylene chloride/methanol (19:1) as the eluent. The product, 0.8 g of brown oil, was dissolved in a 40-fold amount of ethanol, treated with 1.1 equivalents of a saturated solution of fumaric acid in ethanol and concentrated to a volume of 10 ml. There was obtained 0.8 g of 6-(3,4-dimethoxyphenyl)-3,4-dihydro-1-methylpyrrolo[1,2-a]pyrazine fumarate (1:1.3); m.pt.: 158°-160° C. (dec.). A sample was recrystallized from a 40-fold amount of ethanol and yielded the (1:1) fumarate which melted at 160°-161° C. with decomposition.

Provenance & Evidence