NO129852B - - Google Patents

Description

Method for the production of

condensation products of phenols and

polyacetate acetic acid esters.

It is known from German interpretation document no. 1,093,377

that one can carry out the condensation of phenol with levulinic acid in 37-40% hydrochloric acid as a catalyst at 40-80°C.

It turns out that this method is not applicable for the condensation of phenols with polyacetoacetic acid esters, as the polyacetoacetic acid ester is saponified with the aqueous hydrochloric acid above 20°C. The acetoacetic acid formed is not stable and breaks down immediately

in acetone and carbon dioxide. The acetone is condensed again with phenols in the presence of hydrogen chloride to bis(4-hydroxy-phenyl)-dimethylmethane or its derivatives.

From US patent no. 3.H2 7,345 it is known to condense phenols with esters of levulinic acid in the presence of gaseous hydrogen chloride at temperatures in the range of 0°C to room temperature and with a sulfur compound (e.g. mercaptoacetic acid) as a catalyst. However, it has been shown that ethyl mercaptan is a significantly better condensation catalyst for condensations of polyacetoacetic acid ester with o-tert.butylphenol, while mercaptoacetic acid is particularly effective when levulinic acid is used.

In DAS No. 1,213,852 the condensation of phenols with levulinic acid in the presence of methyl mercaptan is mentioned and it is expressly stated here that only methyl mercaptan is effective, but not the next homologue, namely ethyl mercaptan. There was therefore a prejudice against the method according to the invention.

Application no. 3881/70 relates to a process for the production of condensation products of phenols and monoacetic acid esters.

It has now surprisingly been found that the saponification of the polyacetate acetic acid ester can be prevented when the condensation is carried out at a low temperature. However, since the condensation at low temperature only proceeds slowly, ethyl mercaptan is added as a catalyst

for faster setting of the equilibrium.

The object of the invention is a method for producing condensation products of phenols with the general

formula

and polyacetate esters of the general formula II

where R^ and R2 mean hydrogen atoms, the same or different alkyl residues with 1-4 carbon atoms, R3 a saturated, linear or branched aliphatic, aromatic, araliphatic or cycloaliphatic hydrocarbon residue with 2 to 12 carbon atoms and n means 2-4, wherein

the method is characterized in that the condensation is carried out in the presence of gaseous hydrogen chloride at a temperature from -10 to +15°C and in the presence of ethyl mercaptan, in amounts from 0.05 to 0.5% by weight, referred to the polyacetate ester used.

For the condensation, e.g. the following phenols: phenol, o-cresol, 2-isopropyl-, 2-sec.butyl-, 2-tert.butyl-, 2-methyl-4-sec.butyl-, 2-methyl-4-tert.butyl-, 2,6-dimethyl-, 2,6-diisopropyl-phenol.

The production of the polyacetate acetic acid ester takes place by adding diketenes to the polyol. Basic compounds are used as catalysts, e.g. triethylamine. High-melting polyols are dissolved in solvents inert to the diketene and then deposited on the diketene.

Suitable polyols for the production of polyacetate esters are, for example, ethylene glycol, propanediol, butanediol-(1,4), hexanediol-(1,6), decanediol-(1,10), dodecanediol-(1,12), 2,2-dimethyl- propanediol-(1,3), trimethylolpropane, glycerin, pentaerythritol, quinine, 1,4-dimethylolcyclohexane, 1,1,4,4-tetramethylolcyclohexane. For the production of aromatic polyacetoacetic acid esters, e.g. hydroquinone, resorcinol and dioxynaphthalenes.

The method according to the invention is carried out so that one per acetoacetyl group uses 3-4 moles of phenol of the general formula I and condenses in the presence of dry hydrogen chloride gas under normal pressure with 0.05-0.5% by weight of ethyl mercaptan referred to the polyacetoacetic acid ester used, at -10 to +15°C, preferably at 10°C . It is also possible to work under a hydrogen chloride overpressure of 1-3 atm., conditions which are preferably used in technical production. Essential to this method is the exact observance of the temperature. Already at 20°C, a partial saponification of the polyacetate acetic acid ester occurs. The yields are therefore considerably lower at condensation temperatures above 20°C than at temperatures below 20°C. Due to the low condensation temperatures, it is sometimes necessary to work with a solvent such as e.g. methylene chloride, toluene or anisole.

After completion of condensation, the dissolved hydrogen chloride, water and mercaptan are removed under a water jet pump vacuum between 10 and 20°C. Excess phenol is then removed by vacuum distillation at 100-180°C. The mostly resinous residue is recrystallized from an organic solvent or precipitated from the solution by the addition of a polar solvent.

The aforementioned polyphenol carboxylic acid esters find a wide variety of uses. They can e.g. find use for the stabilization of plastics, as a fungicide and bactericidal agent or for the production of varnish resins.

The table below shows the refractive index at 20°C, respectively the melting point for polyacetate esters that were used in examples 1 to 9.

Example 1.

Bis/^ 3 , 3-bis(4'-hydroxy-3'-tert.butyl-phenyl-butanoic acid/-glycol ester.

In the reaction flask are 1200 g of o-tert.butylphenol (8 mol)' and 230 g of ethylene glycol-1,2-bis(acetoacetic acid ester), n^ 2 0 = 1.4535

(1 mole). The reaction mixture is cooled to 10°C, 1.14 g of ethyl mercaptan is added and then dry hydrogen chloride is introduced to saturation. When cooling with ice water, the condensation temperature is kept at 10°C for 24 hours. The aqueous hydrochloric acid is removed with a water jet pump at 15-20°C. The temperature is then slowly increased to 180°C

and distills off excess o-tert.butylphenol. After cooling the resin-like crude product is recrystallized from toluene. Yield: 595 g (= 75% referred to acetate acetate).

Temp. 134°C.

Analysis: <C>50<H>66°8 Calculated: C 75.5% H 8.3%

Found: C 75.9% H 8.3%.

Comparison test to example 1.

a) Condensation at 40°C.

600 g o-tert.butylphenol (4 mol), 115 g ethylene glycol

1,2-bis(acetoacetic acid ester) (0.5 mol) and 0.57 g of ethyl mercaptan are mixed and condensed for 24 hours at 40°C. During the condensation, a weak stream of hydrogen chloride is passed through the mixture from time to time. Processing takes place as described in example 1.

Yield: 71 g (18% referred to the acetic acid ester used).

Temp. 116°C.

b) Condensation without ethyl mercaptan.

600 g o-tert.butyl-phenol and 115 g ethylene glycol-1,2 -

bis(acetoacetic acid ester) is mixed and saturated with hydrogen chloride gas. The condensation time is 72 hours at 10°C. The preparation takes place as described in example 1. Yield: 65 g (16% referred to the acetic acid ester used).

Temp. 130°C.

Example 2.

Bis/_ 3 , 3-bis (4'-hydroxy-3'-t.butyl-phenyl)-butanoic acid 7-butanediol ester-(1,4).

Analogous to example 1, the reaction of 450 g of o-tert.butylphenol (3 mol), 129 g of butanediol-1,4-bis(acetacetate)

(0.5 mol) and 0.64 g of ethyl mercaptan in the presence of hydrogen chloride at 10°C gave after 24 hours 390 g of a resin-like product. After recrystallization, 2 88 g (70% referred to acetate acetate) appeared

of a white, crystalline compound with m.p. 120°C.

Analysis: C^H^Og Calculated: C 76.0% H 8.5%

Found: C 75.4% H 8.3%

Example 3.

Bis/_ 3 , 3-bis ( 4 1 -hydroxy-3-tert. butylphenyl)-butanoic acid/-hexanediol ester-(1, 6) ■

Analogous to example 1, a mixture was condensed

of 450 g of o-tert.butylphenol (3 mol), 143 g of hexanediol-1,6-bis(acetoacetic acid ester) (0.5 mol) and 0.6 g of ethyl mercaptan at 10°C with hydrogen chloride for 18 hours. After distilling off water and excess o-tert-butylphenol, 390 g of a brown, brittle resin appeared. After recrystallization from acetone, 272 g (64% referred to acetic acid ester) of a crystalline product of m.p. 104°C.

Analysis: C^H.^0 Calculated: C 76.0%' H 8.7%

Found: C 7 5.2% H 8.1%

Example 4.

Bis/_— 3 , 3-bis ( 4 1 -hydroxy-3-tert. butyl phenyl)-but ans yre7-2 , 2-dimethyl-propanediol ester-( 1 , 3 ).

450 g of o-tert.butylphenol (3 mol), 136 g of 2,2-dimethyl-propanediol-1,3-bis(acetoacetic acid ester) (^ mol) and 0.68 g of ethyl mercaptan are mixed together, saturated at 10°C with hydrogen chloride and condensed for 28 hours at 10°C. The work-up takes place as described in example 1. The crude product was recrystallized from toluene. Yield: 302 g (62% referred to acetate acetate).

Temp. 96°C.

Analysis: C53H72<O>g Calculated: C 76.2% H 8.6%

Found: C 77.0% H 8.9%

Example 5.

Tetra/3,3-bis(4'-hydroxy-3'-tert.butylphenyl)-butanoic acid 7-penta-erythritol ester.

900 g of o-tert.butylphenol (6 mol), 2 36 g of pentaerythritol tetra(acetoacetic acid ester) (J mol) and 1.2 g of ethyl mercaptan are condensed with stirring and saturated with hydrogen chloride at 10° C. for 24 hours. After removal of hydrochloric acid, water and o-tert.butylphenol, 696 g of a red resin are formed (crude yield 87% referred to acetic acid ester). The crude product is dissolved in toluene. After a longer delay, part of the pure product crystallizes out. When the hexane is precipitated, a further part is recovered from the mother liquor.

Yield: 557 g (69% referred to the acetic acid ester used).

Temp. 2 30°C.

Analysis: <C>ioiHl'!2°16 Calculated: C 75.9% H 8.2%

Found: C 75.4% H 8.3%

Example 6.

Tetra[_~3 , 3-bis(4'-hydroxy-3'-t.butylphenyl)-butanoic acid 7-1,1,4,4-tetramethylolcyclohexane ester.

Dissolve 180 g o-tert.butylphenol (1^2 mol), 54 g tetramethylolcyclohexane-tetra-1,1,4,4-(acetoacetic acid ester) (0.1 mol), 0.3 g ethyl mercaptan in 100 ml methylene chloride, cool to 10°C, saturated with hydrogen chloride gas and condensed for 24 hours at 10°C. After distillation of hydrochloric acid and excess phenol, 146 g of crude product are obtained. The raw product is dissolved in benzene and heated for 20 minutes with clay soil until boiling. After filtering off and precipitation with hexane, 88 g (53% referred to the acetic acid ester used) of a crystalline product with m.p. 148°C.

Analysis: <C>i06<H>140°16 Calculated: C 76.2% H 8.4%

Found: C 75.3% H 8.3%.

Example 7.

Bis/~3,3-bis(2'-hydroxy-3'-methyl-5'-t.butyl-phenyl)-butanoic acid 7-butanediol ester-( 1, 4).

Analogously to example 1, reaction is carried out with 4&2 g of 2-methyl-4-t.butylphenol (3 mol), 129 g of butanediol-1,4-bis(acetoacetic acid ester) (0.5 mol) and 0.6 4 g of ethyl mercaptan in the presence of hydrogen chloride gas at 10°C, and 48 hours condensation time gives after recrystallization from cyclohexane 15 3 g (35% referred to the acetoacetic acid ester used) bis-/_ 3,3-bis(2'-hydroxy-3'-methyl-5'- t .butyl-phenyl-butanoic acid/-butanediol ester-(1,4).

Temp. 161°C.

Analysis: C56H78°8 Calculated: c 76.6% H 8.8%

Found: C 75.8% H 8.6%

Example 8.

Bis/_ 3 , 3-bis (4'-hydroxy-3'-t.butyl-phenyl)butanoic acid/-1,4-dimethylol-cyclohexane ester..

In a reaction flask, 400 g of o-tert.butylphenol (2.66 mol), 104 g of cyclohexane-1,4-bis(a-ethylacetic acid ester) (1/3 mol) and 0.38 g of ethyl mercaptan are mixed and condensed at 10°C for 48 hours with gaseous hydrogen chloride. After completion of the reaction, the aqueous hydrochloric acid is removed, first with a water jet pump between 10 and 20°C; then the temperature is slowly increased to 180°C and the vacuum is lowered to 1 torr. The distillation residue is a yellow-brown colored brittle resin. The residue is dissolved in toluene and precipitated by adding hexane as a crystalline powder.

Yield: 230 g (78% referred to the acetoacetic acid ester used).

Temp. 115°C.

Analysis: <C>56<H>76°8 Calculated: C 76.6% H 8.6%

Found: C 75.9% H 8.7%

Example 9.

Bis 1_ 3 , 3-bis (4'-hydroxy-3*- tert .butyl-phenyl)-butanoic acid 7-cyclo-hexane ester-( 1, 4).

In the same way as described in example 8, condense

600 g of o-tert.butyl-phenol (4 mol), 142 g of cyclohexanediol-1,4-bis(acetoacetic acid ester) (0.5 mol) and 0.38 g of ethyl mercaptan at 0°C in the presence of hydrogen chloride gas for 40 hours. After distillation of hydrochloric acid and o-tert.butyl-phenol, 420 g of crude product are recovered in the form of a brittle resin. After dissolution in toluene and precipitation with hexane, the crystalline bis/<->3,3-bis(4'-hydroxy-3'-

tert.butyl-phenyl)-butanoic acid/-cyclohexane-ester-(1,4). Yield: 220 g (52% referred to the acetoacetic acid ester used). Temp. 110°C.

Analysis: C54H72°8 Calculated: C 76.5% H 8.5%

Found: C 76.4% H 8.5%

Claims (1)

Process for the preparation of condensation products of phenols of the general formula I and polyacetoacetic acid esters of the general formula II where and R2 means hydrogen atoms, same or different alkyl residues with 1 to 4 carbon atoms, R^ means a saturated, linear or branched aliphatic, aromatic, araliphatic or cycloaliphatic hydrocarbon residue with 2 to 12 carbon atoms and n is 2-4, characterized in that the condensation is carried out in the presence of gaseous hydrogen chloride at a temperature from -10 to +15°C and in the presence of ethyl mercaptan in amounts from 0.05 to 0.5 percent by weight, referred to the polyacetate ester used.