PRODUCTION OF TRIMETHYLHYDROQUINONE

    公开(公告)号:JPH1053548A

    公开(公告)日:1998-02-24

    申请号:JP12040397

    申请日:1997-05-12

    Applicant: DEGUSSA

    Abstract: PROBLEM TO BE SOLVED: To obtain the subject compound in high yield by reacting a trimethylcyclohexenedione with an acylating agent in the presence of a protonic acid. SOLUTION: 3,3,5-Trimethylcyclohex-2-ene-1,4-dione is reacted with an acylating agent in the presence of a protonic acid and the formed trimethylhydroquinone ester is successively saponified to give the objective compound. A trifluoromethanesulfonic acid, chlorosulfonic acid, polyphosphoric acid, fuming sulfuric acid or a mixture of these acids is used as the protonic acid. The amount of the acylating agent is 2-4mol based on 1mol of 3,5,5- trimethylcyclohex-2-ene-1,4-dione and that of the acid is 0.1-50wt.%. The saponification is carried out in the presence of a phase mediation agent (e.g. n-butanol). The amount of the acid used is reduced and the saponification can also be extremely readily carried out.

    4.
    发明专利
    未知

    公开(公告)号:DK1092700T3

    公开(公告)日:2004-02-16

    申请号:DK00121161

    申请日:2000-09-29

    Applicant: DEGUSSA

    Abstract: A process for the preparation of unsaturated 4,5-alleneketones comprises reaction of a tertiary propargylalcohol with an alkenylalkylether or a ketal in the presence of an aliphatic sulfonic acid or salt. A process for the preparation of unsaturated 4,5-alleneketones (I) of formula (1) comprises reaction of a tertiary propargylalcohol of formula (2) with an alkenylalkylether of formula (3) or a ketal of formula (4) in the presence of an aliphatic sulfonic acid of formula (5) or sulfonic acid salt of formula (6). An Independent claim is included for a process for the preparation of unsaturated 3,5-dieneketones and their corresponding saturated ketones by isomerization or hydrogenation of 4,5-alleneketones (I) of formula (1). R -O-C(R )=CH-R (3), R SO3H (5), R SO3M (6) R , R = H, 1-20C alkyl, aryl or alkylaryl or R and R may combine to form a 5-6 membered ring; R , R = 1-4C alkyl; R ,R = 1-4C alkyl; R , R = halogen, 1-20C alkyl or cycloalkyl optionally substituted with halogen, R is additionally an optionally substituted aryl; and M = cation of an organic or inorganic base.

    Procedimiento para la preparación de metionina

    公开(公告)号:ES2662937T3

    公开(公告)日:2018-04-10

    申请号:ES13706017

    申请日:2013-02-26

    Abstract: procedimiento para la preparación de D,L-metionina, en el cual se alimenta dióxido de carbono a una disolución acuosa de metioninato de potasio obtenida por hidrólisis de 5-(2-metilmercaptoetil)hidantoína, a fin de precipitar la metionina bruta, que se separa y purifica, en el que, para los fines de purificación, se prepara una disolución acuosa de la metionina bruta separada y se somete a recristalización, caracterizado por que la disolución a partir de la cual tiene lugar la recristalización contiene un antiespumante, iones de potasio y también un aditivo de cristalización, en el que el antiespumante comprende aceite de silicona, y en el que el aditivo de cristalización es un tensioactivo aniónico, o una mezcla de diferentes tensioactivos aniónicos, y por que la recristalización tiene lugar introduciendo una disolución de metionina caliente a 60 a 110ºC en una suspensión de metionina tibia a 35 a 80ºC, cuya temperatura es menor que aquella de la disolución introducida, manteniéndose la temperatura de la suspensión de metionina entre 35 y 80ºC durante la adición, caracterizado por que el aditivo de cristalización es uno de los compuestos mostrados en las fórmulas 1 a 3, o una mezcla de los mismos: R1-O-SO3M (fórmula 1) R2-O-(CH2)n-SO3M (fórmula 2) R3-(O-C2H4)n-O-SO3M (fórmula 3) en las que n es un número entero de 1 a 12, M es sodio o potasio, y R1, R2 y R3 son un grupo alquilo de C8 a C20 lineal, ramificado o cíclico, saturado o insaturado, o un grupo arilo.

    10.
    发明专利
    未知

    公开(公告)号:DE10121058A1

    公开(公告)日:2002-10-31

    申请号:DE10121058

    申请日:2001-04-28

    Applicant: DEGUSSA

    Abstract: A process for the preparation of beta,gamma,delta-unsaturated ketones and/or alpha,beta,gamma,delta-unsaturated ketones by the reaction of an unsaturated alcohol with an enol ether or mixture of enol ethers, with formation of ketals as a by-product, at temperatures of from 50° C. to 200° C., in the presence of an acid catalyst, whereby one or all of the reagents is/are heated to the reaction temperature of from 50° C. to 200° C. before the acid catalyst is added.

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