A novel process can be used for a heterogeneously catalysed oxidation reaction, in the presence of a pulverulent noble metal-containing catalyst, where (meth)acrolein, an alkyl alcohol, in particular methanol, and an oxygen-containing gas are converted to an alkyl (meth)acrylate, in particular methyl (meth)acrylate. A corresponding reactor suitable for performing the reaction is also useful. The process allows for an effective retention of the particulate catalyst and the continuous discharge of fines fractions of the catalyst powder which are present, particularly in a fresh catalyst batch as a consequence of its preparation. Such fines fractions may also be produced by abrasion during the reaction. The process allows for effective recycling, recovery, and utilization of these discharged catalyst fractions.

A novel process can be used for a heterogeneously catalysed oxidation reaction, in the presence of a pulverulent noble metal-containing catalyst, where (meth)acrolein, an alkyl alcohol, in particular methanol, and an oxygen-containing gas are converted to an alkyl (meth)acrylate, in particular methyl (meth)acrylate. A corresponding reactor suitable for performing the reaction is also useful. The process allows for an effective retention of the particulate catalyst and the continuous discharge of fines fractions of the catalyst powder which are present, particularly in a fresh catalyst batch as a consequence of its preparation. Such fines fractions may also be produced by abrasion during the reaction. The process allows for effective recycling, recovery, and utilization of these discharged catalyst fractions.

The present invention provides a process for preparing a diester compound of the following general formula (1), having a dimethylcyclobutane ring, wherein R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, the process comprising reacting a dimethylcyclobutanone compound of the following general formula (2), wherein R.sup.1 is as defined above, with a phosphonic ester compound of the following general formula (3), wherein R.sup.2 and R.sup.3 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, to produce the diester compound (1), having a dimethylcyclobutane ring.

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The present invention provides a process for preparing a diester compound of the following general formula (1), having a dimethylcyclobutane ring, wherein R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, the process comprising reacting a dimethylcyclobutanone compound of the following general formula (2), wherein R.sup.1 is as defined above, with a phosphonic ester compound of the following general formula (3), wherein R.sup.2 and R.sup.3 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, to produce the diester compound (1), having a dimethylcyclobutane ring.

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The invention discloses a method for preparing maleate by selective catalytic oxidation of lignin. The method uses a heteropolyacid functionalized ionic liquid as a catalyst, and an aqueous alcohol solution as a reaction medium to achieve high-efficiency selective catalytic conversion and ring opening oxidation of biomass lignin at a reaction temperature of 110-160 C. and an oxygen pressure of 0.5-1.0 MPa for 1-6 h. The selectivity of maleate is higher than 47.83%. The yield and selectivity of a single chemical derived from the depolymerization of lignin in the present invention are much higher than the prior art, and the ionic liquid catalyst exhibits outstanding advantages such as availability of recovery and recycling through simple temperature adjustment; the reaction conditions of the present invention are mild, and the process is green and safe, easy to operate, and available for batch and continuous production. The invention provides a new green way for preparing bulk chemicals like maleate from reproducible raw materials such as lignin.

Through an intermediate I (a compound having the structural formula as shown in the formula Ia and/or the formula Ib), or a pharmaceutically acceptable salt thereof, or a solvate thereof, and a tautomer Ic of Ib, a bicyclopyrone intermediate II with a high yield can be prepared. Two compounds are docked first under the action of a base to produce an intermediate I, and then the intermediate I is subjected to intramolecular ring closure by an ammonium salt, which can increase the yield of the bicyclopyrone intermediate (II), reduce side reactions, and reduce problems that a reaction of raw materials is easily incomplete due to intramolecular ring closure directly through an ammonium salt. A one-pot method includes producing an intermediate I under the action of a base and then performing a ring-closure reaction to produce a bicyclopyrone intermediate (II) that reduces side reactions, and further increases the yield.

Through an intermediate I (a compound having the structural formula as shown in the formula Ia and/or the formula Ib), or a pharmaceutically acceptable salt thereof, or a solvate thereof, and a tautomer Ic of Ib, a bicyclopyrone intermediate II with a high yield can be prepared. Two compounds are docked first under the action of a base to produce an intermediate I, and then the intermediate I is subjected to intramolecular ring closure by an ammonium salt, which can increase the yield of the bicyclopyrone intermediate (II), reduce side reactions, and reduce problems that a reaction of raw materials is easily incomplete due to intramolecular ring closure directly through an ammonium salt. A one-pot method includes producing an intermediate I under the action of a base and then performing a ring-closure reaction to produce a bicyclopyrone intermediate (II) that reduces side reactions, and further increases the yield.

A process for continuously removing water in situ from an oxidative esterification reaction is provided. The process includes (a) conducting a first oxidative esterification reaction in a first reactor or reaction zone, wherein the total number of reactors or reaction zones is n and n is at least 2; (b) removing a crude product stream from the first reactor or reaction zone; (c) introducing the crude product stream to a distillation column to generate a column overheads stream and a column bottoms stream; (d) passing a portion of the columns bottoms stream to the product recovery zone; and (e) passing a portion of the column overheads stream to a subsequent reactor or reaction zone. Steps (a)-(e) can be repeated.

A process for continuously removing water in situ from an oxidative esterification reaction is provided. The process includes (a) conducting a first oxidative esterification reaction in a first reactor or reaction zone, wherein the total number of reactors or reaction zones is n and n is at least 2; (b) removing a crude product stream from the first reactor or reaction zone; (c) introducing the crude product stream to a distillation column to generate a column overheads stream and a column bottoms stream; (d) passing a portion of the columns bottoms stream to the product recovery zone; and (e) passing a portion of the column overheads stream to a subsequent reactor or reaction zone. Steps (a)-(e) can be repeated.

The invention relates to a process for the production of 1,6-difunctionalized hexane derivatives from 1,3-diunsaturated hydrocarbons, preferably butadiene, wherein a hydroformylation with carbon monoxide and hydrogen is performed in the presence of an at least dihydric alkanol and during the hydroformylation the temperature is increased. The reaction yields the acetals of the 1,6-hexanedial derivatives which are isolated and further reacted to obtain the desired 1,6-difunctionalized hexane derivatives, in particular 1,6-hexanediamine, 1,6-hexanediol and adipic acid.