Pyridine → p-Nitrophenyl 5-benzyloxy-2,2-dimethyl-7-(1,1-dimethylheptyl)-3,4-dihydro-2H-benzopyran-4-carboxylate

関与物質

反応手順

A mixture of 3.3 g (7.53 mmole) 5-benzyloxy-2,2-dimethyl-7-(1,1-dimethylheptyl)-3,4-dihydro-2H-benzopyran-4-carboxylic acid, 5.0 g (21.3 mmole) p-nitrophenyl trifluoroacetate and 100 ml dry pyridine, under nitrogen, is stirred at room temperature for three hours. The pyridine is evaporated in vacuo, ethyl ether is added to the residue and this is washed with 1N sodium hydroxide, water, 10% hydrochloric acid, brine, dried (MgSO4) and the solvent evaporated to obtain 4.5 g crude oil. This is taken up in pentane and cooled to obtain 3.38 g of crystals, m.p. 87°-87.5° C.

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