Water → 2,3-Dihydro-1H-3a,5-diaza-cyclopenta[a]indene

Participants

Reaction Steps

A mixture of 0.2885 g bis(triphenylphosphine) palladium dichloride and 0.1565 g copper (I) iodide in 200 mL triethylamine was heated to reflux for 20 min. To the resulting solution was added at room temperature 25.00 g N-(4-iodo-3-pyridinyl)-2,2-dimethyl-propanamide and 25.3 g 5-chloro-1-pentyne and the mixture was heated to reflux for 30 min. The reaction mixture was distributed between water and ethyl acetate, the phases were separated and the organic phase was washed with water and brine, dried over magnesium sulfate and evaporated. The residue was taken up in 200 mL tert-butanol and 18.45 g powdered potassium hydroxyde was added. The mixture was heated to reflux for 30 min. The reaction mixture was distributed between water and ethyl acetate, the phases were separated and the organic phase was washed with water and brine, dried over magnesium sulfate and evaporated. The residue was purified by chromatography on silica gel with ethyl acetate:methanol=7:3 to yield 7.37 g 2,3-Dihydro-1H-3a,5-diaza-cyclopenta[a]indene as slightly yellow solid melting at 90-91° C.

Provenance & Evidence