DE1947644C - Process for the preparation of m-hydroxy benzoic acid - Google Patents

Description

(> ζ · η rI:, '.-! i .or λ .re: ./ e -.> .re ere? e: t Lncem d.:t;o:-.>r;.Viknor.en. and therefore μΊΙιγ ihrr (til'lun

Γΐΐ. ^ Γ :. ^Γ .ϋ '· errr.'i ..'., '.- .; λ-fie ~ .χ r. '. Jr.i ::: croLk-n O \ v vi.it w.ssn stem definitely vermirdi-κ λι-μΙ'ιι

'.! e .-. jer. .er ^ j-'ie !. '!.: e. ie :. gee: c :: e: e- \ 'irf.ü'.ri: ·. Π. » K: Each ι Oxvd.ilion per MuI, -iiylierlr-, m Kn->, i

ι .. ■■■ - ■ lie- .'eil.: ._ '_'jb The \ erh.rJ.r. £ wc>: K ", i Viol W .i> v.-r is formed, can (Ίι'-ιιίΙ. <-Il.n

'. her, Terr.r.-jr .t; Γ ·. ·: ι. at cie'e "their is ^ n'irii ¹ .. ί dime." :. J.-u'h llvdrolvse from not um ("·. '" T / l · ι:

'..:. ■■■ -. '. I! p-! l .. 'Jr ■ ■' ... r. he / -.--!: _: =. >: / n - .. ". '. er n: \ .- v K ¹ VN [.-!.;. <l and manufactured in-Ai yln» ■ yi »* n / <. i

i'e .-- r ^r .- '. ·: ·: Γ · .. ^Γ . _μ '/ ίΐ. ¹ ;! / ·. · ¹ .. · .- '■: ^. ;;. Ν; . "V'.i'.i Η.: Λ" - v, u-iv ·.% ■! '.'. Iet w.-uien. For this reason, ν.ιι- am ι

'-j -.!. ν.-; _; af e: t;:; f D-: ■.;:! 4 -. l :: e ~ -r. er. * .. ::, - ::. .-... · v »■ .- £ ■» -! ·. li.-i presence of free m-Kif.nl. 'la.

e ■ _ ■: ■;. '· - ·' :: ·;. ':. ■:' ■: · '·. . 'j :' gr ._ :: er._i J..rr uv -> :. ·: ... v. ; iK \, -i ■ /! • .r.Ti.t'.iini '. ml of raw material of the f>/>fl; tIμm.

. :. · ...:; .- ..! ■ -! -Lr -.--: '· e.-r; ir.c .. ". £ er:>: · ..-; vrAi;. · :: .-: -, ih.ii! I" ii is , the reaction runs mam lnn.il

Ij .. i-.ei .jri'ite rei: -. '.:. le .-: _ r.ä>: Iv. üe \ ί;:. ·.: ·; ·. ·. · ■. ·.;.: ·, '. : \\ ' lV ^ ti.ilh are Jie reaction conditions ,

/. 'Mjr.t'ji!r.i'c -.-, Γ. ; T.-f {jCr>. ">Rr".:.;■> ...: c rv ^ :. ·: · .: .. ·:.: «.I! Ii .-: i. .iU ^; «Las lelative s'errelation of llydp <l. m-

'ier ^c -. .if'iii: er .: -. 2 ". ■ '. Be'-Γ eI"r; .. ·· ... ^; j: \'. s.-. 'ov-v.!; » :: ·. J ι ν; .ν ν-; t jui ( > \ N ilatioiisgesi. Hwindij4 f if inoj '

.re:. Ij. : ■ - ':.'. .:.: ..:. s c.zit- '' · i ~ '...':::; ■: *: c.:v ·. ν .-; ■, · -> P:, - K .-. iktu'Hstv-mper.iiur is ho: -i-.irii. '-Iv..ι

/.J -h -: ■ .-: · .-. ■ ·.: .. '.:;.; .-. D ^: _ ΐ; -: ..- :; ··. :: ^; .:. ·; ν:;. · .ν ', Vi' liiul ν, μ; Notes about f. () to IIO <. hm you:

Consumption of r ^ .- cherder>jhv; efi. <A. :: v. :: - .. i a \\ \\ <, \\ i. tlv.hoh> »-} -: <■ ··«. speed as small as possible / n h.ilicn

<jie little Sciek!: '.: ili four B :: i. ::. c \ v- ·. M .-. A-S.ii,. »:; I'm ts-i such low temperatures a linhc G / .v

-äüre 'Aährer.d dir S _.: \:.: i:.: - c. wi.i tv;.: .-.:, »; .- ;: vi .iiUioiisfc-vvtiwiiuiigkcit to achieve it is nntwcmlij '

greater. Ms:; before. Ν; ~ ·;: · .Γί.: 'Ν.:. ^ -. ·. <:' Ϊ.ν: -. Ν.! Ί ··, ', ίν; '.' rmru S.-hucnnet: illegal containing Kalaly.alor um!

ό-s: -'-. If il ^ i-.rr.i-izs -_r.jd :; N. ': «;: ^; ^ ;;! ri-.:n OwdiitionvK-accelerated to be used.

• '., - ■, "• -rjtjr. Di ZiZi-. ..O' -. Er. Pr ...- 'v; :: · ..:': -..- <he lc ·; ' .-! - IVr used catalyst is an iibh'h'i O <y

r-erjii rer, biiiä'.v;:; .-: d.itionsk.ualvs.itor and contains vanadium. ( Ιιγίιιι.

Ar.ce.-er-e :: ^:>: er ·. Xerf.i rc :. :. :: M: r «: j: l; nii; by Mani.in. Cobalt. Nickel. Copper 'κΙ'.τ ' A <Ajl>'\: r. \

ΓΓ: -. Η ;. ü "■> >. . · R-er.ü. "I? Ä '.. re ^; \. Ϊ: ν :. S.-: Je :: ·.! Ii-Krv-sol sj ixfcr a L'iemis.: H same . Kob; ill-, alz ': oiln K'.l »ali-

: r. i'er Λ! \ α '-;~~; .Γί, ~ \ ;. Jir: w; -J. JiJ.vh Nvird oxides are particularly cheap because they Ιιί'.Ιι .ίΜγ / niiti

(J: - ·; - '· er:' jhrer.; - -Jcr Techr-.v rich: d.irchccfiihrt. Are cheap. The catalyst is in Ιιίππ; ρ ": ιι ·: ι

Cj. J .. "- i. T'.ri Me- ge ν.> Η Ne ^ -. Re.i's'.ionsprodiikteu. Solution used in the reaction mixture. Di · - Μ ·: μ (; <;

Aie J '.. :: - ..: r: ce \ i'r: ivi.: Nge :, -.:nd condensation of the catalyst used is in the ΙΚτίι'.Ιι, mi

pr ·,: '·.:. ·. see: .. 30 0.02 to 2 gram atoms, and preferablyv.eisc in. M ': f: i'.h

L- -.- .. irJe r.Ljη a N'erfahre :. to the iier> tellurg of from 0.05 to> 0.5 gram atoms in K ■ 11:> Iy -, - ii ^ r.

Γί-Μ. Jr. '\. hen /, e- · ... re found, i.e. calculated to 1 mole of m-acyloxytoluene. Vcr - /.! Ii ':' l '.- ii <;

ke: i: -. ze: .h: iet i-.t. daIi ri.in a m-Acv] oxvtoluene, the FJeschlcunii "-! - = r. · J

si.!; ■■ ' · η of a fatty acid with 2 to 5 carbon atoms known. These include aliphaticc Aldcir.d ·; '.'J' .- r

• ■ derives Henz.csäure, with oxygen or a 35 ketone, including methyl ethyl ketone. Cnttr <\ <-. -,·-.· 1.

Free oxygen-containing gas in the presence of a lower aliphatic aldehydes are he. ' r / u; '! <'.; ■.

Solution. a heavy metal catalyst · and they are highly active at low temperatures -, ι, ν! D-;

(The data accelerator in the homegenerate, liquid use of acetaldehyde is particularly ^ j :; Ίν.

Phase oxidized at temperatures up to about 130 C and since this is easily accessible. The Merij used. ". ·

The amount of m-avloxv, benzoic acid obtained by heating 40 is preferably in a range of not less

in less mineral acid or alkali solution hydrolv- than 0.1 mole per mole to be oxidized m-Acvloxv-

sated. The al starting material used m- \ cyl-toluene. The accelerator is (. Learning reaction system

nxvti'luol can easily be added continuously or periodically by acylation vi> n m-cresol.

getting produced. [read solvents used for the driving

The acylation of m-creole is not only described as a catalyst, it is also said to be m-white. z. It. With acid anhydrides or acid aloxvtoluene as well as those used as accelerators (! found, carried out. Aldehydes are suitable as a solvent, and a large amount of water should not be used contain anhydrides or halides of aliphatic carbon. Examples of solvents are low acidic, z. B. acetic acid. Propionic acid, n- or isomolecular aliphatic carboxylic acids, e.g. B. lissighuttcrsätirc or u- or nco-valeric acid c. and 50 acid. Propionic acid, n- or iso-i-buttic acid and aromatic carboxylic acids. z. II. Benzoin ^ äiirc. Under n- or nco- \ aleric acid c. Ls is recommended ilic, cn is a small amount of acetic acid aiihvdride for commercial purposes in addition to the solvent most suitable. of the anhydride to add the same acid, with

With regard to the oxygenation reaction, however, the solubility of the heavy metal alkaline agent should be

that as the raw material of the Oxvdationsrcaklioi. The larger the anhydride line, the less it becomes

used, acylated m-cresol not more than 0.1 Gc- For this reason, the molar proportion of the

contain largely free m-cresol. Given hydrids no more than a fivefold of the whole dissolution

if necessary, rectification or another detergent is required. Per 1 mole of m-acyloxyloluene

proceed as required. Lin used by the reaction from 1 to .10 moles of solvent.

m-cresol and an excess amount of liquid acetic acid- Äo The molecular used as an oxidizing agent

m-Accloxytoluene mixture produced by anhydride ent- Oxygen can be oxygen gas, air or another

envelope generally be less than 0.1 percent by weight mixture of oxygen with an inert gas,

free m-cresol. based on in aceloxytoluene, and that, however, no oxydalion-inhibiting substances,

does not contain water and inorganic substances, such as sulfur compounds and water, in grollen

so that the m-Accloxytoluolgcmisch obtained may contain 1111 different amounts. Iki the use of l.tifl

changes as raw material (for oxylulion reaction without it is recommended to

Kcinigiing is used. gen alkali solution / ti wash and then / u

ü 1. "! ih.jii; ^{.. f11} '·· ■ •' • bonds oxy-dry,

The oxidation can take place under atmospheric pressure _Ώ ·. ·, Ι ι

(Hler on an industrial scale at a higher ^pi

Pressure up to 20 kg / cm ² can be carried out. 850 parts of acetyl chloride were heated with cooling

Preferably, 1080 parts of m-cresol are added dropwise to the reaction system for 1 hour. withdrawing agent which reacts in situ with water, 5 After the addition, the mixture was added for 30 minutes like an acid anhydride or acid halide, heated ^{to 50 ° C.} The reaction mixture was washed with a hydroxide solution in order to intercept the 1000 parts of an aqueous 2 percent sodium water formed in the course of the oxidation reaction and the reaction proceeded smoothly. To let when rectifying received. The dehydrating agent is added before or 1400 parts of a fraction from boiling point 212 after the start of the reaction in a calculated 10 to 214 ° C., which corresponds to the boiling point of m-acetoxytoluene that the catalyst in the reaction corresponds. The fraction contained 0.03% free cresol. system does not fail. The addition of the dehydrating 100 parts of cobalt (II) acetate ■ 4H ₂ O were dissolved in 2500 parts of glacial acetic acid continuously during the reaction, and oxygen was carried out periodically. utes at a temperature of 90 ⁰ C under violent

A cobalt (III) salt is preferably introduced into the solution as a catalyst for stirring. During the initial use, which was carried out by oxidizing a cobalt (fl) conduction of oxygen, 18 parts of "freshly distilled salt" were obtained, and rd by mixing it with the above-mentioned acetaldehyde in four individual portions in the above-mentioned oxidizing agent in the presence of the solvent of 10 minutes added. The previously reddening agent and accelerator oxidized. This light purple colored solution was 15 minutes after the process is called "activation" 20 the addition of the first portion black-brown and after using the activated catalyst 40 minutes dark green With this the activation of the induction period of the oxidation reaction was reached.
be fingered that it is almost negligible. After the complete activation, the catalog was

The oxidation reaction can also be heated to 70 ° C. using a solution and a mixture of preparation of a catalyst that does not activate 25 600 parts of the m-acetoxytoluene solution with 400 parts has been subjected to. In this glacial acetic acid while introducing oxygen In this case, however, the induction period is added dropwise a few times up to 30 minutes. During the reaction was-Cinige Dozen times as long as the activation ends at 20 minute intervals, 4 parts each |> period, which is usually 30 minutes to 2 hours of acetaldehyde added to the reaction system, and in lasting, sometimes occurring at varying intervals of 1 hour, were maintained Side fractions, including the hydrolysis of the progress of the reaction, each 55 parts of vinegar «Jes m-acyloxytoluene, and therefore added to acidic anhydride. From the beginning of the procedure If the yields of m-acyloxybenzoic acid were satisfactory, the reaction had to be heated for 1 hour, leads. then the temperature of the reactor system began

Depending on the reaction conditions, it takes the time to rise gradually from 3 to

generally about 4 to 18 hours to cool 6 hours after the start of the reaction. One

In Acvloxytoluol-converted in excess of 99 ° / _0th An analysis after 8 hours of reaction time showed that

Reaction time of longer than 24 hours leads to the content of unreacted m-acetoxytoluene in the

Side reaction products and is therefore not emp- reaction system was less than 0.1% and that

l worth it. 40 more than 99% of the m-acetoxytoluoIs had been converted.

The reaction mixture obtained after the oxidation, 845 parts of a solution obtained by distilling off, is subjected to hydrolysis. It is advantageous to remove the largest part of the solvent from the reaction mixture before the hydrofoil was removed with 16 (50 parts of an aqueous 32prolysc by distillation the liquid was then either cooled from the mainly m-hydroxy wedge to room temperature and the oxidation product formed containing licium oxide was filtered off before the cobalt hydroxyl precipitate.
llydrolysis or afterwards from the hydrolysis reaction. The filtrate was separated off with concentrated hydrochloric acid to a mixture. added to a pH of 6, and four parts

The hydrolvsercakt'on is extracted in the presence of 50 free cresol with benzene. The clinic acid, such as sulfuric acid and hydrochloric acid, or the permanent aqueous layer, was brought to a pH value of 1.5 with a concentrated excess of a base such as sodium hydroxide or hydrochloric acid. In doing so, The m-hydroxyhynzoic acid obtained formed a crystalline precipitate. The mixture from which it was used was cooled to 10 ° C., and 505 parts of the crystalline reaction mixture obtained by crystallization under KiHi-55 m-hydroxybenzocic acid were obtained by filtration and resumed when bases were used. The precipitate of cobalt hydroxide was acidified and then precipitated while cooling, dissolved in acetic acid and was recovered during the subsequent process and then filtered. The obtained Ni-Hydroxy-Oxydaüonsrcnktion be reused,
benzoic acid is then, r. I). purified by recrystallization, 3050 parts from the oxidation reaction mixture. 60% acetic acid contained 0.3% water and

The filtrate of the reaction mixture contains low-could also be used as a solvent in the

molecular aliphntischc carboxylic acids, a small subsequent oxidation can be used.

Amount of cresol, tn-hydroxybenzoic acid, ni'Acyloxy · „. · 1 2

Benzoic acid and dissolved Schwermctullkiitalysatorcii, example

which can be isolated, 65 108 parts of m-cresol were refluxed with

The examples illustrate the invention. Percent and 212 parts of acetic anhydride acetylated. The received Unless otherwise stated, parts of the data relate to the reaction mixture contained 0.02% free cresol,

is puf the weight, 7.5 parts of cobalt (II) 'hydroxide were in 360 parts

Claims (6)

Glacial acetic acid dissolved, and a stream of air was passed through for 60 minutes at a temperature of 100.degree. C. with vigorous stirring in order to activate the potassium hydroxide. During activation, 0.9 parts of acetaldehyde were added to the solution over a period of 10 minutes. The activated catalyst solution was admixed with the acetylation reaction mixture obtained and the oxidation reaction was carried out at a temperature of 95 to 1000 ° C. by means of air, while 0.5 part of acetaldehyde was added at intervals of 15 minutes. The air introduced into the reaction system was previously passed through an aqueous alkaline solution and dried with calcium chloride. The reaction was carried out for 14 hours at a slight excess pressure of 50 mm Hg until unreacted m-acetoxytoluene was only present in traces. The solvent was distilled off and 200 parts of residue were obtained. 20 parts of concentrated hydrochloric acid were added to the residue and the mixture was warmed to HO0C for 30 minutes. When the hydrolysis reaction mixture cooled, the hydrochloric acid layer assumed a deep blue color because of the cobalt content. A soft organic material deposited. The hydrochloric acid layer was removed by decanting,. and 100 parts of 10% hydrochloric acid were added to the organic material. The mixture was refluxed and stirred for 21 hours. The organic material was originally dispersed in a semi-molten form and was converted to finely crystalline m-hydroxybenzoic acid at the end of the reaction. The reaction mixture was cooled and filtered. 113 parts of m-hydroxybenzoic acid were obtained. The filtrate contained acetic acid and a small amount of cresol. 45 parts of acetic acid and 1.2 parts of ir-KresJ were obtained by extraction with ethyl acetate. Patent claims: 1. Process for the production of m-hydroxybenzoic acid, characterized, that one is a m-acyloxytoluene, which is different from a Fatty acid with 2 to 5 carbon atoms or benzoic acid, with oxygen or a free one Oxygen-containing gas in the presence of a solvent, a heavy metal catalyst and an oxidation accelerator in homogeneous, liquid phase is oxidized at temperatures up to about 130 'C and the resulting m-acyloxybenzoic acid hydrolyzed by heating in an aqueous mineral acid or alkali solution. 2. The method according to claim 1, characterized in that there is used as heavy metal catalysts Salts or oxides of vanadium, chromium, manganese, cobalt, nickel, copper or molybdenum or their Mixtures used. 3. The method according to Ans [vuch 1, characterized in that that a cobalt (I II) salt is used as a heavy .Tietallcatalyst, which is produced by oxidation a cobalt (l l) salt with molecular oxygen under heating in a homogeneous, liquid phase in the presence of an accelerator and a solvent has been made. 4. The method according to claim 1, characterized in that the Ojzydationsreaktion in the presence a lower fatty acid with 2 to 5 carbon atoms as a solvent. 5. The method according to claim 1, characterized in that the oxidation reaction in Carries out the presence of a dehydrating agent. 6. The method according to claim 1, characterized in that the m-acyloxytoluene to be oxidized the oxidation reaction in the form of a reaction mixture of m-cresol and an excess Amount of acetic anhydride supplies.