Ammonia → HCID 66585081, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 66.9 g (193 mmol) of tert-butyl{2-[2-chloro-4-cyano-3-phenyl-1H-pyrrol-1-yl]ethyl}carbamate in 150 ml of ethanol are added slowly 688 ml (2670 mmol) of aqueous 4N hydrochloric acid solution and the mixture is heated to 90° C. Evolution of gas is rapidly observed, and after 1 hour, the medium is clear. 6.44 g (71.5 mmol) of paraformaldehyde are then added and heating is continued for a further 4 hours. After cooling, the reaction medium is basified slowly by adding aqueous ammonia, the product is extracted with dichloromethane, the organic phase is dried over sodium sulfate and the solvent is evaporated off under reduced pressure to give a yellow solid, which is triturated in acetonitrile and then isolated by filtration. The filtrate is concentrated under reduced pressure and the solid residue obtained is triturated in acetonitrile and then isolated by filtration. The two batches of solid are combined to give 30.6 g of 6-chloro-7-phenyl-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-8-carbonitrile in the form of a beige-coloured powder after drying.

Provenance & Evidence