Method for preparing substituted styrene derivatives

Patent metadata

Field	Value
Publication number	US-10384995-B2
Application number	US-201716324159-A
Country	US
Kind code	B2
Filing date	Aug 7, 2017
Priority date	Aug 12, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

The present invention relates to a method for preparing substituted styrene derivatives.

First claim

The invention claimed is:

1. A method for preparing substituted styrene derivative of formula (I):

where
R 1 is Cl (Ia), Br (Ib) or methyl (Ic),
comprising reacting a dihydrobenzofuran derivative of formula (II)

where
R 1 is Cl, Br or methyl,
by heating in the presence of an alkoxide or hydroxide base
to give a compound of formula (I).

2. The method according to claim 1 , wherein the radical definitions of formulae (I) and (II) are as follows:
R 1 is Cl.

3. The method according to claim 1 , wherein the base used is potassium tert-butoxide, sodium tert-butoxide, sodium methoxide, sodium ethoxide, potassium methoxide or potassium hydroxide.

4. The method according to claim 1 , further comprising using one or more of an amide or ether solvent or mixtures of amide solvents with ethers or aromatic solvents as solvent.

5. The method according to claim 1 , further comprising using one or more solvents comprising one or more of DMAc, DMF or diglyme or mixtures of DMAc or DMF with THF, 2-methyl-THF, dioxane, DME, toluene, xylene, chlorobenzene or 1,2-dichlorobenzene.

6. The method according to claim 1 , wherein one of the following combinations of solvent and base is used for the reaction:
a) diglyme in combination with potassium hydroxide
b) DMAc in combination with potassium hydroxide
c) DMF in combination with potassium hydroxide
d) solvent mixture of DMAc with toluene, xylene, chlorobenzene, 1,2-dichlorobenzene, dioxane, DME, 2-methyl-THF or THF in combination with potassium hydroxide
e) solvent mixture of DMF with toluene, xylene, chlorobenzene, 1,2-dichlorobenzene, dioxane, DME, 2-methyl-THF or THF in combination with potassium hydroxide
f) DMAc, DMF, THF, 2-methyl-THF, dioxane, DME, anisole or diglyme or mixtures of these solvents in combination with potassium tert-butoxide
g) potassium hydroxide as inorganic base and potassium tert-butoxide as organic base.

Assignees

• Bayer Cropscience Ag

Inventors

• Gallenkamp Daniel
• Ford Mark James

Classifications

• C07C39/373

  with all hydroxy groups on non-condensed rings and with unsaturation outside the aromatic rings · CPC title

• C07C39/20

  Hydroxy-styrenes · CPC title

• C07C33/28

  Alcohols containing only six-membered aromatic rings as cyclic part with unsaturation outside the aromatic rings · CPC title

• C07C37/06

  by conversion of non-aromatic six-membered rings or of such rings formed in situ into aromatic six-membered rings, e.g. by dehydrogenation · CPC title

• C07C309/66

  Methanesulfonates · CPC title