Process for preparing 4,4'-dihydroxybiphenyl

    公开(公告)号:US5091592A

    公开(公告)日:1992-02-25

    申请号:US641899

    申请日:1991-01-16

    IPC分类号: C07C37/08 C07C39/15

    CPC分类号: C07C39/15

    摘要: A process for preparing 4,4'-dihydroxybiphenyl comprising oxidizing 4,4'-diisopropylbiphenyl with molecular oxygen and decomposing the resulting oxidation product in the presence of an acid catalyst is disclosed, in which oxidation of 4,4'-diisopropylbiphenyl is carried out in the presence of ammonia or an ammonium salt. The oxidation product has an increased selectivity of 4,4'-diisopropylbiphenyl dihydroperoxide and, therefore, produces the desired product in high yield upon acid decomposition.

    Process for preparing 2,6-naphthalenedicarboxylic acid
    4.
    发明授权
    Process for preparing 2,6-naphthalenedicarboxylic acid 失效
    制备2,6-萘二甲酸的方法

    公开(公告)号:US5175352A

    公开(公告)日:1992-12-29

    申请号:US817347

    申请日:1992-01-06

    IPC分类号: C07C51/265

    CPC分类号: C07C51/265

    摘要: A process for preparing 2,6-naphthalenedicarboxylic acid comprising oxidation reaction of 2,6-diisopropylnaphthalene or an oxidation product thereof with molecular oxygen in a solvent containing an aliphatic carboxylic acid in the presence of a catalyst comprising cobalt and manganese as heavy metals and a bromine compound is disclosed, in which said oxidation reaction is carried out in the presence of at least one nitrogen-containing compound selected from the group consisting of a pyridine compound, ammonia, a carboxylic acid ammonium salt, urea, a urea derivative, an amine, and a carboxylic acid amide. 2,6-Naphthalenedicarboxylic acid can be obtained at higher purity and in increased yield.

    Process for purification of naphthalenedicarboxylic acid
    9.
    发明授权
    Process for purification of naphthalenedicarboxylic acid 失效
    萘二羧酸的纯化方法

    公开(公告)号:US5344969A

    公开(公告)日:1994-09-06

    申请号:US983411

    申请日:1992-11-30

    IPC分类号: C07C51/43

    CPC分类号: C07C51/43

    摘要: A process for purifying a crude naphthalenedicarboxylic acid containing impurities and coloring substances obtained by the oxidation of a di-substituted naphthalene, dispense with the use of a large amount of alkali or acid, and producing a naphthalenedicarboxylic acid having a high purity and good color effectively and in a high recovery is disclosed, which comprises dissolving the crude naphthalenedicarboxylic acid in a mixed solvent comprising an amine compound and an alcohol and conducting crystallization.

    摘要翻译: 一种纯化含有杂质的粗萘二甲酸和通过二取代萘氧化得到的着色物质的方法,省去了大量的碱或酸,并且有效地制备了纯度高,颜色好的萘二羧酸 并且公开了高回收率,其包括将粗萘二甲酸溶解在包含胺化合物和醇的混合溶剂中并进行结晶。