Sulfuric Acid → Methyl 7-amino-1,2,3,3a,4,5-hexahydropyrrolo[1,2-a]quinoline-6-carboxylate

Participants

Reaction Steps

Sulphuric acid (5 mL) was added carefully to a solution of methyl 7-(2,2-dimethyl-propionylamino)-1,2,3,3a,4,5-hexahydropyrrolo[1,2-a]quinoline-6-carboxylate (Intermediate 34, 0.820 g) in methanol (50 mL) and and the resultant mixture was stirred and heated at reflux for 4 hours then left at room temperature for 4 days. The mixture was then heated at reflux for a further 1.5 hours. After cooling the solution was evaporated in vacuo and the residue was partitioned between ethyl acetate and water and basified with 20% aqueous sodium hydroxide solution. The organic layer was dried (Na2SO4) and filtered and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-30% to give methyl 7-amino-1,2,3,3a,4,5-hexahydro-pyrrolo[1,2-a]quinoline-6-carboxylate (0.580 g) as a yellow gum.

Provenance & Evidence