Method for producing arylpropenes

Patent metadata

Field	Value
Publication number	US-2016332944-A1
Application number	US-201515111841-A
Country	US
Kind code	A1
Filing date	Jan 16, 2015
Priority date	Jan 17, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

The present invention relates to a process for preparing arylpropenes, especially 1-methoxy-4-(1-propenyl)benzene (anethole), by means of thermolysis of the corresponding 1,1-diarylpropanes.

First claim

1 .- 13 . (canceled)

14 . A process for preparing arylpropenes of the formula (I)

in which
k has the values of 0, 1, 2 or 3 and
R 1 is independently selected from the group consisting of C 1 -C 6 -alkoxy, di(C 1 -C 6 -alkyl)amines and hydroxyl,
comprising thermolyzing at least one 1,1-diarylpropane compound of the formula (II)

in which k and R 1 have the definitions given above,
wherein the compound of the formula II in the gas phase is contacted with at least one solid acidic oxidic catalyst in a reaction zone.

15 . The process according to claim 14 , wherein, in the formulae I and II, k=1 and R 1 is hydroxyl or C 1 -C 6 -alkoxy.

16 . The process according to claim 14 , wherein the 1,1-diarylpropane compounds (II) comprise, to an extent of at least 50 mol %, based on the total amount of the compounds of the formula II, compounds of the formula (II.a)

in which both R 1 are the same.

17 . The process according to claim 14 , wherein the reaction zone is supplied, together with the compound of the formula II, additionally with at least one solvent S.

18 . The process according to claim 17 , wherein the solvent S is water.

19 . The process according to claim 17 , wherein the mass ratio of solvent S to the compound of the formula II is in the range from 20:1 to 1:100.

20 . The process according to claim 14 , wherein the catalyst comprises silicon dioxide.

21 . The process according to claim 20 , wherein the catalyst is a silica which has optionally been impregnated with one or more inorganic acids.

22 . The process according to claim 14 , wherein the compound of the formula II is contacted with the catalyst at a temperature in the range from 250 to 650° C.

23 . The process according to claim 14 , wherein the compound of the formula II is conducted continuously through the reaction zone comprising the solid oxidic catalyst.

24 . The process according to claim 23 , wherein the compound of the formula II is supplied continuously to the reaction zone and the reaction product is quenched immediately after leaving the reaction zone.

25 . The process according to claim 23 , wherein the compound of the formula II is supplied to the reaction zone with the aid of a carrier gas.

26 . The process according to claim 23 , wherein the compound of the formula II is conducted through the reaction zone with a catalyst load of 0.01 to 5 kg of compound II per kg of catalyst and hour.

27 . The process according to claim 14 , wherein, in the formulae I and II, k=1 and R 1 is hydroxyl or methoxy.

Assignees

• Basf Se

Inventors

• Rüdenauer Stefan
• Lanver Andreas
• Pelzer Ralf
• Ebel Klaus

Classifications

• C07C41/18 Primary

  by reactions not forming ether-oxygen bonds · CPC title

• C07C67/00

  Preparation of carboxylic acid esters · CPC title

• C07C43/215

  having unsaturation outside the six-membered aromatic rings · CPC title

• C07C43/20

  having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring · CPC title