Calciumoxide → HCID 21269259, compound

Participants

Reaction Steps

A mixture of 48 parts of methyl 1-(8-chloro-2,3-dihydro-6-nitro-4H-1-benzopyran-4-yl)-1H-imidazole-5-carboxylate, 8 parts of calcium oxide and 400 parts of methanol was hydrogenated at normal pressure and at room temperature with 2 parts of palladium-on-charcoal catalyst 5%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was taken up in trichloromethane. The organic layer was washed with water and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (90:10 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was converted into the hydrochloride salt in a mixture of 2-propanol and 2,2'-oxybispropane. The salt was filtered off and salt overnight in vacuo at 80° C., yielding 18.3 parts (35.3%) of methyl 1-(6-amino-2,3-dihydro-4H-1-benzopyran-4-yl)-1H-imidazole-5-carboxylate monohydrochloride.2-propanolate (1:1 ); mp. 146.0° C. (compound 1.135).

Provenance & Evidence