摘要:
A process for preparing substituted imidazoles of the formula I ##STR1## R.sup.1, R.sup.2 and R.sup.3 are identical or different and are each hydrogen, halogen, NO.sub.2, CN or a C.sub.1 -C.sub.20 -hydrocarbon radical which is unsubstituted or substituted by one or more halogens or R.sup.1 and R.sup.2 together are members of a 3- to 20-membered hydrocarbon ring which is unsubstituted or substituted by one or more halogens and/or C.sub.1 -C.sub.8 -alkyl groups and which may contain 1, 2 or 3 heteroatoms from the group consisting of nitrogen, oxygen and sulfur, andR.sup.4 is a C.sub.1 -C.sub.20 -hydrocarbon radical which is unsubstituted or substituted by one or more halogens,comprises using an aqueous phase of the imidazoles of the formula II ##STR2## where R.sup.1, R.sup.2 and R.sup.3 are as defined above with compounds of the formula IIIR.sup.4 --O--R.sup.5 IIIwhereR.sup.4 is as defined above andR.sup.5 is hydrogen or R.sup.4, it being possible in the latter case for the two R.sup.4 substituents to be identical or different,and reacting it at from 200.degree. to 550.degree. C. in the presence of a catalyst comprising oxides and/or phosphates of one or more metals of the 2nd, 3rd and 4th main group and the 4th subgroup of the Periodic Table in the presence or absence of phosphoric acid and/or phosphoric esters.
摘要:
A process for the preparation of enol ethers of the general formula I ##STR1## in which R.sup.1,R.sup.2,R.sup.3,R.sup.4,R.sup.5 denote C.sub.1 -C.sub.20 alkyl, C.sub.1 -C.sub.20 alkenyl, or C.sub.7 -C.sub.20 phenylalkyl, R.sup.2,R.sup.3,R.sup.4 denote hydrogen, aryl, cyano, --COOR.sup.5, C.sub.1 -C.sub.12 alkyl monosubstituted to trisubstituted or interrupted by --COOR.sup.5, --C.dbd.O, cyano, or C.sub.1 -C.sub.12 alkoxy, C.sub.1 -C.sub.12 alkyl monosubstituted to trisubstituted by --COOR.sup.5, --C.dbd.O, cyano, or C.sub.1 -C.sub.12 alkyl, or C.sub.7 -C.sub.20 phenylalkyl and R.sup.2 and R.sup.4 or R.sup.3 and R.sup.4 together form a C.sub.3 -C.sub.10 alkylene chain or a C.sub.2 -C.sub.20 alkylidene chain, from acetals or ketals.
摘要:
A process for preparing and/or working up mixtures by (meth)acrylic acid and/or (meth)acrylic ester in the presence of at least one polymerization inhibitor and at least one oxygenous gas, which comprises metering in at least part of the oxygenous gas at an exit rate of at least 50 mm/s.
摘要:
A process for the preparation of an N-alkyl- or N-phenylalkyl-substituted pyrazole I by reacting the corresponding N-unsubstituted pyrazole II with an alcohol III of the formula R.sup.1 --OH where R.sup.1 is the same alkyl or phenylalkyl group to be added to the unsubstituted nitrogen group --NH-- of the pyrazole reactant. Both of the reactants, i.e. the pyrazole II and alcohol III compounds, are catalytically reacted in the liquid phase in a molar ratio of from 0.001:1 to 1:1, at temperatures of 50.degree.-400.degree. C. and under a subatmosheric pressure of from 0.8 bar up to a superatmospheric pressure of 250 bar. The catalyst required for this liquid phase reaction is selected as being at least one or more non-heterogeneous acid catalysts, their alkyl esters or their acid anhydrides.
摘要:
A separating column containing a sequence of mass transfer trays that are supported by at least one covered double-T support and/or covered U-shaped support.
摘要:
The present invention relates to novel mixtures of (meth)acrylic esters of polyalkoxylated trimethylolpropane of the formula where AO is for each AO independently at each instance EO, PO or BO where EO is O—CH2-CH2- PO is independently at each instance O—CH2-CH(CH3)- or O—CH(CH3)-CH2- BO is independently at each instance O—CH2-CH(CH2-CH3)- or O—CH(CH2-CH3)-CH2- p1+p2+p3 is 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 or 75, R1, R2 and R3 are independently H or CH3, a simplified process for preparing these ester mixtures and the use of reaction mixtures thus obtainable.
摘要:
A clamp for detachable connection of a column tray to a support ring in a column. The clamp includes a bolt lower clamp part connected to the bolt. The lower clamp part has at least one orifice through which a liquid present in the column can flow away.
摘要:
The invention relates to processes for preparing water absorbing polymers by polymerization of a monomer solution comprising allyl acrylate and/or allyl alcohol, the solution comprising not more than 0.002% by weight of allyl acrylate and/or allyl alcohol, based on acrylic acid, to aqueous monomer solutions for producing water absorbing polymers, to water absorbing polymers, to processes for producing hygiene articles and also to hygiene articles.
摘要:
The present invention relates to novel (meth)acrylic esters of polyalkoxylated trimethylolpropane of the formula where AO is for each AO independently at each instance EO, PO or BO where EO is O—CH2-CH2- PO is independently at each instance O—CH2-CH(CH3)- or O—CH(CH3)-CH2- BO is independently at each instance O—CH2-CH(CH2-CH3)- or O—CH(CH2-CH3)-CH2- p1+p2+p3 is 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 or 75, R1, R2 and R3 are independently H or CH3, a simplified process for preparing these esters and the use of reaction mixtures thus obtainable.
摘要:
The present invention relates to novel tocopherol-containing superabsorbents, to a process for preparing them using tocopherol-containing acid-functional monomers, especially acrylic acid, and to their use for absorbing aqueous fluids.