4-Chloro-2-hydroxybenzaldehyde → 1-[1-(tert-butoxycarbonyl)piperidin-4-ylmethyl]-4-(7-chloro-2H-benzopyran-3-sulfonyl)-2-piperazinone

Participants

Reaction Steps

To a solution of the obtained 1-[1-(tert-butoxycarbonyl)piperidin-4-ylmethyl]-4-vinylsulfonyl-2-piperazinone (3.99 g) and 4-chlorosalicylaldehyde (1.61 g) in tert-butanol (35 ml) was added potassium t-butoxide (446 mg), and the mixture was refluxed for 4 days. The reaction solution was concentrated, and the residue was partitioned with ethyl acetate/water. The organic layer was washed with brine, dried and concentrated, and the residue was purified with silica gel column chromatography (hexane:ethyl acetate=1:4) to give colorless solid of 1-[1-(tert-butoxycarbonyl)piperidin-4-ylmethyl]-4-(7-chloro-2H-benzopyran-3-sulfonyl)-2-piperazinone (1.856 g).

Provenance & Evidence