1-溴-6-氰基-2-萘酚的合成

Synthesis of 1-Bromo-6-cyano-2-naphthol

以2-萘酚(Ⅱ)为原料,经一锅两步反应制备6-溴-2-萘酚(Ⅳ),收率为89.0%;然后经氰化反应制备6-氰基-2-萘酚(Ⅴ),投料比n(CuCN)∶n(Ⅳ)=1.5∶1时收率为91.2%;最后分别用溴素和N-溴代丁二酰亚胺(NBS)两种不同的溴化试剂制备了1-溴-6-氰基-2-萘酚(Ⅰ)。以溴素为溴化试剂,乙酸为溶剂,n(Br2)∶n(Ⅴ)=1∶1,Ⅰ的收率为89.8%;该法成本较低,适合工业上大规模生产。以NBS为溴化试剂,乙腈为溶剂,n(NBS)∶n(Ⅴ)=1.00∶1.03,收率几乎定量(99.2%);该法条件温和,简单高效,可避免溴素易挥发和吸入毒性大的缺点,更适合实验室小规模合成。

6-Bromo-2-naphthol （ Ⅳ ） was prepared from 2-naphthol（ Ⅱ ） via a two-step one-pot process in a yield of 89.0% ;then,6-cyano-2-naphthol（ V ） was synthesized from IV under the feeding ratio of n（CuCN） ：n（IV） = 1.5：1 in a yield of 91.2%. In the end, the bromination reagents Br2 and NBS were both adopted to prepare 1-bromo-6-cyano-2-naphthol （ I ） from V. In the case of Br2 as bromination reagent, acetic acid as solvent, n （Br2 ）：n （ V ） = 1：1, the yield was 89. 8% ;this process is low-cost and suitable for industrialization. In the case of NBS as bromination reagent, aeetonitrile as solvent, n （NBS） ： n （ V ） = 1.00：1.03, the yield is 99.2% ; this method is mild, simple, efficient for laboratory-scale preparation,in which the problems of volatilization and high inhalation toxicity of Br2 can be avoided.