N-[2-[2-(1,3-Benzodioxol-5-yl)-pyrrol-1-yl]-ethyl]acetamide (1.7 g) was treated with 10 ml of phosphorus oxychloride under argon and boiled for 45 minutes while stirring. The reaction mixture was hydrolyzed at 0° C. with 50 ml of 2N sodium hydroxide solution and 50 ml of 28% sodium hydroxide solution, diluted with 600 ml of water and extracted with methylene chloride (1×100 ml, 2×60 ml). The organic extracts were combined, dried with MgSO4 and freed from solvent. 1.4 g of crude product was dissolved in a 20-fold amount of ethanol and treated with 1.1 equivalents of a saturated solution of fumaric acid in ethanol. There were obtained 1.5 g (66%) of 6-(1,3-benzodioxol-5-yl)-3,4-dihydro-1-methylpyrrolo[1,2-a]pyrazine fumarate (1:1); m.pt.: 191°-193° C. (dec.).
