反应详情

0.28 g (0.87 mmol) of 3,4-dihydro-2,2-dimethyl-3-hydroxy-4-(1-piperidinyl)-6-amino-7-nitro-2H-benzo[b]pyran was dissolved in 44.8 g of ethanol and hydrogen gas was blown in in the presence of 0.20 g of 5% palladium-carbon, as a catalyst, at room temperature for 3 hours under one atmospheric pressure while stirring. The reaction liquid was filtered under suction to remove the catalyst therefrom, and the solvent was removed by distillation to obtain 0.24 g (yield: 95%) of 3,4-dihydro-2,2-dimethyl-3-hydroxy-4-(1-piperidinyl)-6,7-diamino-2H-benzo[b]pyran as a dark red oil. 0.12 g (0.86 mmol) of thionylaniline and 4 g of benzenewere added thereto and heated under reflux for 2.5 hours. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (ethyl acetate-ethanol=1:3) to obtain 60 mg (yield: 23%) of the intended compound as an yellow solid.

1. customThe reaction liquid
2. filtrationwas filtered under suction
3. customto remove the catalyst
4. customthe solvent was removed by distillation