# US 10,501,396 B2 · Continuous production method for 2-methylene alkanals

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- Number: US 10,501,396 B2
- Document ID: US10501396B2
- Status: Granted
- Kind: B2
- Application number: 16/325,950
- Filed: 2017-09-05
- Published: 2019-07-18
- Granted: 2019-12-10
- Earliest claimed: 2016-09-30
- Assignees: Oxea GmbH
- Applicants: OXEA GmbH
- Inventors: Kurt Schalapski; Jan-Henry Rahe; Christoph Balzarek; Gregor Meier; Heinz Strutz
- Web page: https://patentgrep.com/patent/US10501396B2

## CPC

- C07C 45/75: Reactions with formaldehyde
- B01J 19/0013: {Controlling the temperature of the process}
- B01J 19/2415: {Tubular reactors}
- C07C 47/21: with only carbon-to-carbon double bonds as unsaturation
- B01J 2219/00051: Controlling the temperature
- B01J 2219/00164: controlling the flow
- B01J 2219/3322: Co-current flow
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

The present invention relates to the continuous production of 2-methylene alkanals in a tube reactor, wherein in the 2-position non-branched alkanals are reacted with formaldehyde under acid-base catalysis in the presence of secondary amines and carboxylic acids under laminar flow conditions.

## Claims

### Claim 1

A method for producing 2-methylene alkanals of the general formula I
wherein R1 is an aliphatic residue, by reacting alkanals of the general formula II
with an aqueous formaldehyde solution in the presence of at least one secondary amine and at least one carboxylic acid, characterized in that the educts are reacted in a liquid/liquid two-phase system, wherein the reaction is carried out continuously within a tube reactor under laminar flow conditions with a Reynolds number of greater than or equal to 10 and less than or equal to 2320.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the Reynolds number is kept constant within the tube reactor.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the liquid/liquid two-phase system is formed by separately introducing at least one organic and at least one aqueous phase in a co-current flow into the tube reactor.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the carboxylic acid is introduced into the reactor together with the secondary amine dissolved in an organic solvent.

### Claim 5 (depends on 4)

The method according claim 4, wherein the solvent is selected from the group consisting of mono-alcohols with 6 to 12 carbon atoms or mixtures thereof.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the reaction is carried out at a temperature of greater than or equal to 70° C. and less than or equal to 150° C.

### Claim 7 (depends on 1)

The method according to claim 1, wherein no additional surface-active substances are present in the two-phase system.

### Claim 8 (depends on 1)

The method according to claim 1, wherein the tube reactor is operated with a Reynolds number of greater than or equal to 50 and less than or equal to 500.

### Claim 9 (depends on 1)

The method according to claim 1, wherein the reactor load V/Vh with respect to the total mass flow of reactants is greater than or equal to 3.0 h−1 and less than or equal to 42.0 h−1.

### Claim 10 (depends on 1)

The method according to claim 1, wherein the carboxylic acid is selected from the group consisting of aliphatic or aromatic C2-C12 monocarboxylic acids.

### Claim 11 (depends on 1)

The method according to claim 1, wherein the molar ratio of alkanal, formaldehyde in the formalin and secondary amine is in the range from 1:1:0.01 to 1:1.2:0.07.

### Claim 12 (depends on 1)

The method according to claim 1, wherein the residue R1 is an aliphatic C5-C13 hydrocarbon residue.

### Claim 13 (depends on 1)

The method according to claim 1, wherein at least two different alkanals with the same C number and C greater than or equal to 2, are reacted, wherein at least one of the alkanals has a structure according to formula II.

### Claim 14 (depends on 1)

The method according to claim 1, wherein the molar ratio of carboxylic acid to secondary amine is greater than or equal to 0.5 and less than or equal to 2.

### Claim 15 (depends on 13)

The method according to claim 13, wherein one of the alkanals used is n-undecanal.

### Claim 16 (depends on 2)

The method according to claim 2, wherein the reaction is carried out at a temperature of greater than or equal to 70° C. and less than or equal to 150° C.

### Claim 17 (depends on 2)

The method according to claim 2, wherein the tube reactor is operated with a Reynolds number of greater than or equal to 50 and less than or equal to 500.

### Claim 18 (depends on 2)

The method according to claim 2, wherein the reactor load V/Vh with respect to the total mass flow of reactants is greater than or equal to 3.0 h−1 and less than or equal to 42.0 h−1.

### Claim 19 (depends on 2)

The method according to claim 2, wherein the molar ratio of alkanal, formaldehyde in the formalin and secondary amine is in the range from 1:1:0.01 to 1:1.2:0.07.

### Claim 20 (depends on 1)

The method according to claim 1, wherein no surface active substances are added;
the tube reactor is operated with a Reynolds number of greater than or equal to 50 and less than or equal to 500 at a temperature of greater than or equal to 70° C. and less than or equal to 150° C.; the reactor load V/Vh with respect to the total mass flow of reactants is greater than or equal to 3.0 h−1 and less than or equal to 42.0 h−1 and the molar ratio of alkanal, formaldehyde in the formalin and secondary amine is in the range from 1:1:0.01 to 1:1.2:0.07.