Formaldehyde → HCID 19994583, compound

Participants

Reaction Conditions

Reaction Steps

A 500 mL round bottom flask was half-filled with paraformaldehyde (~200 g) and then connected by means of a rubber hose to an acetone-dry ice trap. The trap was fitted with a 100 mL round bottom flask that contained dry dimethylamine hydrochloride (880 mg, 18 mmol. 1.2 eq. with respect to 1-(2-phenylethyl)pyrrolo[1,2-a]pyrazine). The flask containing the dimethylamine hydrochloride was then cooled to -78° C. and the flask containing the paraformaldehyde was heated between 180°-200° C. until an excess of paraformaldehyde had been distilled. The reaction mixture was then allowed to warm to room temperature. The solid mixture was cooled again to -20° C. and a solution of 1-(2-phenylethyl)pyrrolo[1,2-a]pyrazine (2 g., 9 mmol) in 20 mL of dry CH3CN was added. The reaction mixture was allowed to reach room temperature and left stirring at this temperature for 8 hours. A solution of NaOH (5M, 40 mL) was then added. The resulting solution was extracted with ethyl acetate (3×30 mL). The organic extracts were extracted with a solution of HCl (0.1M, 50 mL). The aqueous acid phase was then separated, neutralized with a solution of NaOH (2M, 50 mL) and extracted with ethyl acetate (2×50 mL). The organic extracts were combined, dried over MgSO4 and evaporated to give 1.8 g (73%) of the title compound,

Provenance & Evidence