# US 6,723,883 B1 · Continuous method for production of cinnamaldehyde and dihydrocinnamaldehyde derivatives > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,723,883 B1 - Document ID: US6723883B1 - Status: Granted - Kind: B1 - Application number: 10/110,532 - Filed: 2002-04-15 - Granted: 2004-04-20 - Earliest claimed: 1999-10-14 - Assignees: BASF SE - Inventors: Jörg Therre; Andreas Kramer; Andreas Weiper-Idelmann; Michael Schulik; Regina Benfer; Jürgen Schossig; Mathias Haake; Hans-Georg Göbbel - Web page: https://patentgrep.com/patent/US6723883B1 ## CPC - C07C 45/74: combined with dehydration - C07C 45/62: by hydrogenation of carbon-to-carbon double or triple bonds - C07C 45/73: combined with hydrogenation - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract The present invention relates to a continuous process for the preparation of cinnamaldehyde or cinnamaldehyde derivatives by continuous reaction of benzaldehyde derivatives with alkanals in the presence of bases and optionally subsequent continuous hydrogenation in a circulation reactor in the presence of a suspension catalyst and hydrogen to give dihydrocinnamaldehyde derivatives. ## Claims ### Claim 1 A process for the (a) continuous preparation of a cinnamaldehyde compound of formula I in which R1, R2, R3, R4, R5 and R6, independently of one another, are hydrogen, C1- to C9-alkyl groups or C1-C9-alkoxy groups, by reacting a benzaldehyde compound of formula II with an alkanal of formula III in the presence of a base, which comprises reacting the reactants continuously in a plant consisting of a plurality of reactors in a cascade system, and introducing fractions of the alkanal of formula (III) into more than one of the reactors of the cascade system, and (b) optionally subsequent continuous hydrogenation in a circulation reactor in the presence of a suspension catalyst and hydrogen to give a dihydrocinnamaldehyde compound of formula IV, where R1 to R6 have the meanings given above. ### Claim 2 A process which comprises (a) continuous preparation of a cinnamaldehyde compound of formula I in which R1, R2, R3, R4, R5 and R6, independently of one another, are hydrogen, C1- to C9-alkyl groups or C1-C9-alkoxy groups, by reacting a benzaldehyde compound of formula II with an alkanal of formula III in the presence of a base, which comprises reacting the reactants continuously in a plant consisting of a plurality of reactors in a cascade system, and introducing fractions of the alkanal of formula (III) into more than one of the reactors of the cascade system, and (b) subsequent continuous hydrogenation in a circulation reactor in the presence of a suspension catalyst and hydrogen to give a dihydrocinnamaldehyde compound of formula IV, where R1 to R6 have the meanings given above. ### Claim 3 (depends on 1) A process as claimed in claim 1, wherein the benzaldehyde compound of formula II is benzaldehyde itself, m-isopropylbenzaldehyde, p-isopropylbenzaldehyde, p-tert-butylbenzaldehyde, m-tert-butylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-methylbenzaldehyde, m-anisaldehyde or p-anisaldehyde, or a mixture of 2 or more of these benzaldehyde compounds. ### Claim 4 (depends on 1) A process as claimed in claim 1, wherein the number of reactors used under (a) in the plant is between 2 and 20. ### Claim 5 (depends on 1) A process as claimed in claim 1, wherein the number of reactors used under (a) in the plant is between 2 and 6. ### Claim 6 (depends on 1) A process as claimed in claim 1, wherein the reactors used under (a) are stirred tank reactors, loop reactors, jet loop reactors, jet reactors or tubular reactors, optionally with recirculation circuit. ### Claim 7 (depends on 1) A process as claimed in claim 1, wherein fractions of the alkanal are introduced into each of the reactors used. ### Claim 8 (depends on 1) A process as claimed in claim 1, wherein between 20% and 70% of the total amount of alkanal added is introduced into the first reactor. ### Claim 9 (depends on 1) A process as claimed in claim 1, wherein the process is carried out such that the conversion of the benzaldehyde compound of formula II is between 20% and 95%. ### Claim 10 (depends on 1) A process as claimed in claim 1, wherein the benzaldehyde compound of formula II introduced into the first reactor is in premixed form in a mixture with a fraction of the alkanal. ### Claim 11 (depends on 1) A process as claimed in claim 1, wherein the molar ratio of the benzaldehyde compound of formula II and the alkanal in the reaction mixture is between 5 mol/mol and 100 mol/mol. ### Claim 12 (depends on 2) A process as claimed in claim 2, wherein the dihydrocinnamaldehyde compound is cyclamenaldehyde or lysmeral. ### Claim 13 (depends on 2) A process as claimed in claim 2, wherein the hydrogenation of the cinnamaldehyde compound of formula II is carried out in a suspension reactor with internals without prior purification of the product obtained in (a). ### Claim 14 (depends on 2) A process as claimed in claim 2, wherein the catalyst particles of the hydrogenation (b) have an average particle size of from 0.0001 to 2 mm. ### Claim 15 (depends on 2) A process as claimed in claim 2, wherein the internals used in the hydrogenation reactor under (b) are fabric packings or sheet-metal packings. ### Claim 16 (depends on 2) A process as claimed in claim 2, wherein the superficial velocity of gas phase and liquid phase is more than 50 m3/m2h. ### Claim 17 (depends on 2) A process as claimed in claim 2, wherein the reactor used under (b) is a jet reactor, a bubble-column reactor or a tube-bundle reactor. ### Claim 18 (depends on 2) A process as claimed in claim 2, wherein the suspension catalyst under (b) comprises at least palladium as active component. ### Claim 19 (depends on 18) A process as claimed in claim 18, wherein the proportion of palladium is 0.1 to 10% by weight. ### Claim 20 (depends on 18) A process as claimed in claim 18, wherein the catalyst is used on a support containing SiO2, TiO2, ZrO2, Al2O3 or carbon. ### Claim 21 (depends on 18) A process as claimed in claim 18, wherein the catalyst is used on a support containing activated carbon.