DE1643333A1 - Process for the preparation of phthalic acid phenyl ether derivatives - Google Patents

Description

1643333 FARBENFABRIKEN BAYER AG

LE VERKU S E N -Beyerwerk patent department

^{G / o}

Process for the production of phthalic acid phenyl ether derivatives.

It has been found that one obtains Phenoxyphtalsäureester when one alkali or alkaline earth salts of Hydroxyphtalsäm eestern? In a polar organic solvent at temperatures "wipe 50 and 200 ⁰ C with halogenated and substituted with electron-withdrawing moieties are reacted benzenes. Hydroxyphtalsäureester within the meaning of the invention.sind z. B. Compounds of the general formula

2 "5
In this formula, R and Ir are any aliphatic or

2 3 aromatic hydrocarbon radicals, preferably R and R, which can be the same or different, ®ϊη alkyl radical with 1-6 carbon atoms ο In the alkali or alkaline earth metal salts of these compounds, the OH-foupp® durek Μ @ θ SS ¹ SQtSt ₉ where

109 J; 13/1874

Me is an alkali or alkaline earth metal, preferably sodium or potassium means. Examples of these compounds are 4-Hydroxyphtalsäuredimethylöster, 3-Hydroxyphtalsäurediethylester, or their sodium or potassium salts.

Halogenated benzenes are e.g. B. Compounds of the general formula

R ¹

where I is a halogen, preferably chlorine and R is an electron-withdrawing radical, preferably -NO ₂ , -GN, -GOOR ⁴ (R ⁴ = alkyl, phenyl), -SOpR, -COR. The electron-attracting radical is defined as a radical with (^ p value according to the Hammet equation> 0.20. X is preferably in the ρ or o-position to R. Examples of such compounds are p-nitrochlorobenzene, o-nitrofluorobenzene, p-gyanochlorobenzene , p-Pluorbenzophenon, particularly suitable iat chloro- or fluoronitrobenzene.

The end products obtained correspond to the formula

COOR ²
COOR ⁵

12 3
in which RR and R have the meaning given above.

Examples of the phenoxyphthalic acid esters obtained by the process according to the invention are 4 '-nitro-4-phenoxy-phthalic acid diethyl ester, 2 ^l -nitro-3-phenoxy-phthalic acid diethyl ester _f 4 ^f -Cyano-4-

1 0 V 7 3/1874

phenoxy-phthalic acid dimethyl ester, 4-benzoyl-4-phenoxy-phthalic acid diethyl ester.

Suitable solvents for the process are organic solvents such as dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, Acetonitrile, methyl sulfoxide is particularly suitable.

In general, the process is carried out in such a way that the corresponding alkali metal salt is prepared from a hydroxyphthalic acid ester dissolved in an inert organic solvent such as toluene or benzene by reaction with an aqueous alkali metal hydroxide or an alkali metal alcoholate or an alkali metal. Instead of the alkali compounds, alkaline earth compounds can also be used. Sodium or sodium compounds are preferably used. The alkali metal salt or alkaline earth metal salt of the hydroxyphthalic acid ester thus obtained is then reacted with the halogenated benzene in one of the polar solvents mentioned. This reaction is generally carried out at 50 to 200 ⁰ C. Preference is given to working in this stage with the complete exclusion of water. The water formed in the reaction is then azeotropically distilled off together with the solvent and, after the water has been separated off, returned.

The end point of the reaction can be seen from the neutral reaction of the reaction mixture. From this mixture one can isolate the end products by removing it from the alkali metal halide or alkaline earth metal halide formed in the reaction, for example separated by filtration and then evaporated the remaining solution.

10 'λ' 1 R 7 /,

The end products produced in this way can be used are used as Moluakioid ·, 4'-Nitro-4-phenoxy-phthalic acid dimethyl ester is particularly suitable.

example 1

Preparation of dimethyl 4- (4'-nitrophenoxy) phthalate: 21.2 g (0.1 mol) of dimethyl 4-hydroxyphthalate are dissolved in 100 ml of toluene. 2.3 g (0.1 mol) of sodium are dissolved in 50 ml of methanol and combined with the toluene solution. The methanol is distilled off with most of the toluene and after the addition of a solution of 17.5 g (0.1 mol) of p-chloronitrobenzene in 100 ml of dirne thylsulf oxide is refluxed under nitrogen, the reflux being passed through a water separator . After 3 h the reaction mixture is neutral. The sodium chloride formed is filtered off and the solvent is distilled off in a water jet vacuum. The residue is recrystallized from methanol. Fp 85-87 ⁰ G.
Yield: 27 g.

The I.R. and NMR spectrum agrees with the assumed structure

match. Elemental analysis:

Calc .: 58.0 56 C; 3.9 # H; 33.8 £ 0; £ 4.2 N

Found: £ 58.1 C; 3.8 lbs H; $ 32.1>0; 4.4 Y * N

Example 2

As in Example 1, instead of sodium methylate, a solution of 4.0 g (0.1 mol) of sodium hydroxide in 10 ml of water is used. The water is distilled off azeotropically with the toluene and then the solution of p-chloro-nitrobenzene is added.
Yield: 25 g 1 0 9 Γ 1 3/1 8 7 4

Le A 10 893 - 4 -

Claims (4)

type entitlements ■ * 1. A process for the preparation of Phenoxyphtalsäureestern characterized in that alkali metal or alkaline earth salts of Hydroxyphtalsäureestera in a polar organic solvent at temperatures between 50 and 200 ⁰ G with halogenated and substituted with electron-withdrawing moieties are reacted benzenes. 2. The method according to claim 1, characterized in that p-nitrochlorobenzene with an alkali salt of dimethyl hydroxyphthalate is implemented. 3. The method according to claim 1 and 2, characterized in that dimethyl sulfoxide is used as the solvent. 4. Phenoxyphthalic acid ester of the formula wherein R ¹ -NO ₂ , -CN, -COOR ⁴ ", -SO ₂ R ⁴ " or COR ⁴ "(R ⁴ " = alkyl, phenyl) 2 3
and R and R denote an aliphatic or aromatic hydrocarbon radical. 109B13 / 187A Lt A to 893