A method for preparing .alpha.-naphthol according to the present invention comprises sulphonation of naphthalene with an equimolar amount of a concentrated sulphuric acid at a temperature ranging from 30.degree. to 85.degree. C. for a period of from 60 to 120 minutes in the presence of acetic anhydride whereafter .alpha.in an amount of from 0.5 to 1.5 mole per mole of naphthalene. The resulting naphthalene-.alpha.-sulphonic acid is fused with an alkali taken in an amount of 3-4 moles per mole of naphthalene-.alpha.-sulphonic acid at a temperature ranging from 180.degree. to 285.degree. C. for a period of from 10 to 30 minutes. The resulting melt consisting of the alkali metal .alpha.-naphtholate and the alkali metal sulphite is mixed with a polar solvent; the resulting mixture is acidified with a mineral acid taken in an amount equimolar relative to the alkali metal .alpha.-naphtholate, whereafter.alpha.-naphthol is separated from the resulting suspension. The method according to the present invention makes it possible to increase the yield of .alpha.-naphthol up to 98% of the theoretical amount and produce .alpha.-naththol with a purity of up to 99.5%.
本发明提供了一种制备α-
萘酚的方法,包括在浓
硫酸的等摩尔量存在下,将
萘磺酸化,温度范围为30℃至85℃,时间为60至120分钟,在
乙酸酐的存在下,然后加入0.5至1.5摩尔的α-
萘磺酸。得到的
萘磺酸-α-
磺酸在温度范围为180℃至285℃,时间为10至30分钟的条件下,与取3-4摩尔的碱熔融。得到的熔体由碱
金属α-
萘酚盐和碱
金属
亚硫酸盐组成,与极性溶剂混合;然后用矿物酸酸化,酸量相当于碱
金属α-
萘酚盐的等摩尔量,然后从所得悬浮液中分离出α-
萘酚。本发明的方法可以使α-
萘酚的产量提高到理论量的98%,并生产出纯度高达99.5%的α-
萘酚。