Process for the preparation of 3-acetamido-5-aminobenzoic acid
    4.
    发明授权
    Process for the preparation of 3-acetamido-5-aminobenzoic acid 失效
    3-乙酰氨基-5-氨基苯甲酸的制备方法

    公开(公告)号:US3907880A

    公开(公告)日:1975-09-23

    申请号:US34122473

    申请日:1973-03-14

    Applicant: BOFORS AB

    CPC classification number: C07C233/00

    Abstract: 3-ACETAMIDO-5-AMINOBENZOIC ACID IS A VALUABLE INTERMEDIATE FOR THE PREPARATION OF DRUGS ESPECIALLY FOR CERTAIN TYPES OF IODINE COMPOUNDS WHICH ARE USED AS X-ray contrast agents. According to the present invention it is prepared by acetylating of 3,5diaminobenzoic acid in an aqueous solution in the presence of a mineral acid. The 3-acetamido-5-aminobenzoic acid is then obtained in the form of its salt of the mineral acid from which salt the desired free acid may be recovered by adding a base. The free acid is obtained in high yields and of high purity.

    Abstract translation: 3-乙酰氨基-5-氨基苯甲酸是用于制备药物的有价值的中间体,特别适用于作为X射线造影剂使用的某些类型的碘化合物。 根据本发明,通过在无机酸存在下在水溶液中乙酰化3,5-二氨基苯甲酸来制备。 然后以其无机酸盐的形式获得3-乙酰氨基-5-氨基苯甲酸,通过加入碱可从其中回收所需的游离酸。 以高产率和高纯度获得游离酸。

    METHOD FOR NITRATING MONO-ALKYL-SUBSTITUTED AROMATIC COMPOUNDS

    公开(公告)号:GB1207384A

    公开(公告)日:1970-09-30

    申请号:GB4794767

    申请日:1967-10-20

    Applicant: BOFORS AB

    Abstract: 1,207,384. Nitration of aromatic compounds. BOFORS A.B. 20 Oct., 1967 [20 Oct., 1966], No. 47947/67. Heading C2C. Mono-alkyl substituted nitro compounds are nitrated with nitric acid in the presence of phosphoric acid, the amount and concentration of which is such that at the conclusion of the nitration the P 2 O 5 content in the spent acid does not exceed 82% by weight, preferably 76% by weight. In the examples (a) toluene is nitrated to give mainly o-and p-nitrotoluene with small amounts of m-nitrotoluene; (b) ethyl benzene is nitrated to give mainly o- and p-nitroethylbenzene; (c) isopropyl benzene is nitrated to o- and p-nitro isopropylbenzene; (d) o-nitrotoluene is nitrated to give 2,4- and 2,6-dinitrotoluene; and (e) m-nitrotoluene was nitrated to give 3,4-, 2,3- and 2,5-dinitrotoluene.

    THE PRODUCTION OF NITRO-SUBSTITUTED BENZENE COMPOUNDS

    公开(公告)号:GB1208502A

    公开(公告)日:1970-10-14

    申请号:GB2826268

    申请日:1968-06-13

    Applicant: BOFORS AB

    Abstract: 1,208,502. Production of nitro-substituted benzene compounds. BOFORS A.B. 13 June, 1968 [15 June, 1967], No. 28262/68. Heading C2C. A compound of formula wherein each of the substituents X 1 to X 5 is either a hydrogen atom or a nitro group is prepared by heating a benzene compound having a carboxyl group or an alkyl group convertible to a carboxyl group in the position of the nitro group shown in the structural formula and optionally containing one or more nitro groups, with nitric acid under pressure. The examples describe the preparation of o-, m- and p-dinitrobenzenes and nitrobenzene.

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