公开(公告)号：US3933929A

公开(公告)日：1976-01-20

申请号：US360097

申请日：1973-05-14

Applicant: Gilbert Colovray

Inventor： Gilbert Colovray

IPC: C07C205/22 ,  C07C67/00 ,  C07C201/00 ,  C07C201/16 ,  C07C37/22 ,  C07C37/40

CPC classification number: C07C201/16 ,  C07C201/08 ,  C07C205/22

Abstract: In a purification process for p-nitrophenol obtained by nitration of phenol, separation of crude nitrophenols, steam distillation to remove o-nitrophenol, and cooling the broth obtained when it contains more than 0.5% sodium bisulphite and is at pH 5.4 to 6.4 to deposit crystals of p-nitrophenol, an improvement consists in stirring the crystals with water at 55.degree.-85.degree.C to give a mixture containing 10-40% excess of p-nitrophenol over the solubility at that temperature, separating the upper layer of p-nitrophenol in water obtained, cooling it to 40.degree.-50.degree.C and separating the layer of water in p-nitrophenol, cooling the latter to below 30.degree.C and collecting the crystals deposited.

Abstract translation: 在通过硝化苯酚获得的对硝基苯酚的纯化方法中，分离粗的硝基酚，蒸汽蒸馏以除去邻硝基苯酚，并且当其含有超过0.5％的亚硫酸氢钠时，获得的培养基冷却并且在pH 5.4至6.4下沉积 对硝基苯酚的晶体的改进在于在55℃-85℃下用水搅拌晶体，得到含有10-40％过量的对硝基苯酚的混合物超过该温度下的溶解度， 硝基苯酚在水中的溶液中，冷却至40°-50℃，分离出对硝基苯酚的水层，将其冷却至30℃以下，收集晶体沉积物。