杏耀国际

将二卤或二卤亚甲基在酸性或碱性条件下水解，则生成相应的醛酮。比如9，9-二溴芴在醋酸中，于醋酸钠存在下加热回流即可以良好的收率生成芴酮。

反应实例

p-Clorobenzal cloride was added to a 4-l. wide-mouthed bottlecontaing 400 cc. of concentrated sulfuric , and stirred vigorously (Hood) for five hours. The viscous mixture is thentransferred to a separatory funnel and allowed tostand overnight, after which the lower layer is run slowly, with stirring, into a 3-l. beakerthree-quarters filled with cracked ice. The cream-colored solid obtained whenthe ice has melted is filtered by suction, washed with water, pressed dry onthe funnel, and divided into three equal parts. Each portion is dissolved in aminimum of ether, and the ethersolution is repeatedly shaken with 2 per cent sodium hydroxide solution until acidification of thewashings gives no precipitate of p-chlorobenzoicacid.  After removal of the ether by distillation on a steambath, the residue is did under diminished pressure from a Claisen flask. The yield of p-chlorobenzaldehydedistilling at 108–111°/25 mm. and melting at 46–47°is 76–84 g.(54–60 per cent of the theoretical amount).

Reference:Organic Syntheses, Coll. Vol. 2, p.133; Vol. 12, p.12

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