BE862362A - PROCESS FOR THE PRODUCTION OF INTERMEDIATE OXIDIZATION PRODUCTS OF TOLUENES WITH ETHER BONDS - Google Patents

Description

       

  Process for the production of products

  
oxidation intermediates of toluenes to

  
ether bonds <EMI ID = 1.1>

  
The present invention relates to a process for the production of intermediate oxidation products, such as

  
benzylic alcohols and / or benzaldehydes, having ether bonds.

  
More particularly, the present invention

  
relates to a process for the production of alcohols and / or aldehydes, characterized in that a toluene having a

  
or more ether bonds, in liquid phase, with molecular oxygen, in order to selectively oxidize the bound methyl group

  
with a benzene ring in a hydroxymethyl or formyl group, so as to convert the toluene into the corresponding alcohol and / or aldehyde.

  
Derivatives of benzyl alcohol and benzaldehyde having ether linkages are valuable products as perfumes, medicaments and starting materials for the preparation of other chemicals. More particularly, m-phenoxybenzaldehyde is a very important compound as an intermediate product for obtaining agents

  
of agricultural and horticultural treatments However, the production of these compounds in a good yield is extremely difficult to achieve. Consequently, until now, we had not yet developed an industrial synthesis process, such as that which is the subject of the present invention, according to which one oxidizes

  
the methyl group of a toluene having one or more ether bonds, in liquid phase, with molecular oxygen. Until now, only industrially advantageous was considered

  
an oxidation process according to which an oxidation reagent such as a permanganate was used (German patent

  
1 953 258).

  
It is generally known that when a methylated aromatic compound is oxidized with molecular oxygen, in the liquid phase, in the presence of a redox catalyst, the methyl group

  
of an aromatic compound is converted by oxidation to a carboxyl group via hydroxymethyl and formyl radicals. However, during the implementation of this oxidation process,

  
the rate of oxidation of formyl group to carboxyl group is much faster than the rate of oxidation of methyl group to formyl group. Therefore, the production of formyl compounds (aldehydes) in good yield is extremely difficult to achieve by carrying out the oxidation process in question.

  
 <EMI ID = 2.1>

  
present of industrially feasible preparation process

  
formylated aromatic compounds with good yields, by oxidation of methylated aromatic compounds, in the liquid phase,

  
with molecular oxygen.

  
In order to overcome the difficulty of transformation

  
the methyl group bonded to the aromatic ring to formyl group,

  
the Applicant has carried out extensive research on the autooxidation of toluene derivatives, in the liquid phase, with molecular oxygen. As results obtained as a result of this continued research, it was discovered that when one submitted

  
a toluene having one or more ethe bonds to an auto-oxidation carried out using a relatively large amount of a heavy metal salt, in particular, a cobalt salt, serving as a catalyst, in the presence of a lower saturated fatty acid and / or an anhydride thereof, predominantly an aldehyde formed under reaction conditions using excess oxygen and predominantly alcohol formed under reaction conditions using excess oxygen.

  
to an insufficient amount of oxygen. However, this process is effective for the oxidation of the methyl group of a toluene having an ether radical in the para position but is still unsatisfactory for the oxidation of the methyl group of a toluene having an ether radical in the meta or ortho position thereof. latest. In

  
in the case of an ether radical present in the meta position or in the orthopedic position with respect to the methyl group of toluene, the reaction rate of the oxidation of such a toluene derivative is extremely low compared to the case of the oxidation of a toluene having an ether group in the para position, so that the reaction is neither initiated under low oxygen pressure, nor moderately promoted even under high oxygen pressure, unless operating conditions are adopted severe. Given that

  
side reactions inevitably take place under such severe conditions, however the ether bond tends to break down thus frequently resulting in disruption

  
of the reaction. Therefore, the oxidation of the meta and ortho compounds is dependent on such disadvantages that only slight modification of the reaction conditions causes a large variation in the result of the experiments and the level of selectivity to the final product is considerably reduced. -duit in comparison with the case of the oxidation of para compounds. In the case of the oxidation of meta and ortho compounds, only a very small quantity of impurities already causes a significant modification of the result of the experiments. These disadvantages appear manifestly as a poor reproducibility of the experiments. This phenomenon is notable in the case of meta compounds which are the most difficult to oxidize.

   For example, the liquid phase oxidation of m-phenoxytoluene under oxygen pressure gives, in the best case, a conversion rate of

  
 <EMI ID = 3.1>

  
benzaldehyde. However, in most cases the reaction does not proceed, or, if it does, the reaction stops when a conversion rate of 10 mol% or less is reached, even though the these reactions are carried out under the same reaction conditions. Therefore, the rate of

  
 <EMI ID = 4.1>

  
case. Although many studies have been done in the

  
In order to try to explain the reason why the reproducibility was not good during the oxidation of the meta and ortho compounds, the Applicant did not wish to adopt definitive conclusions. Following further research, carried out with the aim of discovering stable oxidation processes, the applicant ended up discovering a process according to which cobalt and nickel ions could be used as catalyst or according to which the coexistence of serial ions with the catalyst, was effective in achieving stable oxidation. However,

  
 <EMI ID = 5.1>

  
and ortho was not that good. For example, in the case of m-phenoxytoluene, m-phenoxybenzaldehyde was obtained with good re-

  
 <EMI ID = 6.1>

  
and a degree of selectivity of only 17 to 16 mol%. The Applicant has therefore carried its research further with a view to discovering an additive which can serve as a third constituent of the catalyst making it possible to improve the above process and it has therefore discovered, not without surprise, that the existence of a very low amount of a substance providing ions

  
bromine in the reaction system was very efficient for the selective conversion of the so hardly oxidizable methyl radical in meta and ortho compounds to formyl radical. The present invention is therefore based on the above finding.

  
A process for the oxidation of hardly oxidizable compounds in which a bromine compound is added to the liquid phase auto-oxidation system of methylbenzenes, where a salt

  
of cobalt in acetic acid is used as a catalyst, is well known as a process for the production of terephthalic acid and is currently being carried out on a large industrial scale. However, no information has yet been provided, for example, to remarkably increase the level of selectivity towards intermediate oxidation products by adding a very small amount of a compound. bromine

  
to such a system. In accordance with the studies made by the Applicant, it has been recognized that intermediate oxidation products, such as aldehydes, could be produced with

  
a high degree of selectivity (a) by adding a very small amount of a bromine compound to the liquid phase auto-oxidation system for alkyl or aryl ethers of m-cresol, under normal pressure, when one used a cobalt salt as a catalyst and acetic acid as a solvent and (b) in

  
 <EMI ID = 7.1>

  
As a result of the aforementioned experiments, the effects obtained by carrying out the process according to the present invention are completely surprising and cannot be predicted by those skilled in the art.

  
The main object of the present invention is therefore an industrially advantageous process for the production of alcohols and / or aldehydes, characterized in that a toluene having one or more ether bonds is used as the starting substance and in that the this starting material is subjected to self-oxidation with molecular oxygen, so as to convert the material into corresponding intermediate oxidation products, i.e. alcohols and / or aldehydes. The present invention also relates to a process for obtaining aromatic alcohols and / or aldehydes as intermediate oxidation products, with good reproducibility and with a high degree of selectivity and with good yields in which the occurrence of reactions secondary causing the breakdown of the ether bond is inhibited,

   by auto-oxidation of toluenes having ether groups, in the liquid phase, with molecular oxygen, so as to moderately promote auto-oxidation.

  
Other objects, characteristics and advantages of the present invention will emerge in a more complete manner on reading the detailed description which follows.

  
A more particular subject of the present invention is therefore a process for the production of alcohols and / or aldehydes, characterized in that a toluene derivative having one or more ether bonds, corresponding to the following general formula: is subjected:

  

 <EMI ID = 8.1>


  
in which RO represents an ether group where R represents a hydrooarbyl radical having from 1 to 20 carbon atoms which can bear one or more inert substitutes

  
 <EMI ID = 9.1>

  
to an auto-oxidation reaction, in liquid phase, with molecular oxygen, so as to form the corresponding alcohol and / or aldehyde, more particularly characterized in that the oxidation reaction is carried out using a lower saturated fatty acid and / or anhydride thereof, as a solvent, in the presence of a soluble cobalt salt and a substance providing bromine ions, at a temperature

  
 <EMI ID = 10.1>

  
the degree of conversion of the toluene derivative does not exceed 90%.

  
In the toluene derivative of the above general formula which can be used for the purposes of the present invention

  
 <EMI ID = 11.1> <EMI ID = 12.1>

  
reagents and oxidation products. By way of illustrations of suitable hydrocarbyl radicals, mention may be made of alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-hexyl, n-octyl and Isooctyl radicals: cycloalkyl radicals, such as cyclohexyl groups, cyclooctyl, methylcyclohexyl and ethylcyclohexyl; aryl radicals, such as phenyl, tolyl, xylyl, ethylphenyl, n-propylphenyl, isopropylphenyl, butylphenyl, and naphthyl groups, and aralkyl groups, such as benzyl and phenethyl groups.

  
For the purposes of the present invention, these hydrocarbyl groups can be substituted by one or more inert substituents which in no way interfere with the carrying out of the oxidation reaction. As examples of such inert substituents,

  
mention may be made of hydrocarbyloxy radicals having from 1 to 10 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, n-ootyloxy, cyclohexyloxy and oycloalkyl radicals.

  
similar oxy, phenoxy and benzyloxy; hydrocarbyloxy carbonyl radicals, such as methoxycarbonyl, ethoxycarbonyl, n-propoxyoarbonyl, isopropoxycarbonyl, n-butoxycarbonyl and n-octyloxycarbonyl radicals; and halogen atoms,

  
such as chlorine and bromine atoms. Such inert substituents may also be further substituted by a

  
or more similar inert substituents. Hydrocarbyl groups substituted with one or more more reactive substituents

  
 <EMI ID = 13.1>

  
turbid the oxidation reaction, are not suitable as hydrooarbyl radicals R. The free hydroxyl or mercapto group has an inhibitory activity of auto-oxidation and inhibits

  
 <EMI ID = 14.1>

  
the present invention.

  
When carrying out the process according to the present invention, the oxidative reactivity of the toluene derivative possesses

  
 <EMI ID = 15.1>

  
of the starting compound (destruction of the ether bond) tends to occur when the hydrooarbyl group R becomes complicated.

  
Therefore, the reaction does not take place unless one chooses reactive conditions capable of moderately promoting the reaction at low temperatures. The effect obtained by the addition of the bromine compound becomes remarkable when the <EMI ID = 16.1>

  
 <EMI ID = 17.1>

  
too complicated, the synthesis of this starting compound will be very difficult and, moreover, the reactivity and selectivity of such a starting compound will be reduced, even when the addition of the bromine compound is carried out, probably in due to the fact that, .in this case, the decomposition reactions prevail over the oxidation reaction in the case of such a complicated compound. Therefore, it is very preferable that the number of carbon atoms which constitute the hydrocarbyl group R is limited to 12 or less than 12. The beneficial effect obtained by the addition of the bromine compound becomes important when using. a starting compound having, as hydrocarbyl group R, a phenyl, cyclohexyl, n-tolyl or

  
a linear C 1 to case alkyl group

  
The term "substance or compound providing bromine ions" as used herein and the claims which conclude it, is intended to define a material capable of dissolving in the reaction liquid and of providing bromine ions to the reaction liquid. reaction system and will sometimes also be referred to simply as a "brominated compound" or [deg.] [deg.] bromine ion donor ". As examples of a substance providing

  
 <EMI ID = 18.1>

  
bromine compounds? inorganic and organic. The fact that organic compounds, such as bromobenzene and alkyl bromides, give excellent results will be evident from the examples which follow. However, an extraordinarily remarkable effect is obtained by the use of an inorganic bromide, such as hydrobromic acid, an alkali metal bromide or an alkaline earth metal bromide. Due to the solubility, cost and ease of handling, the use, as bromine ion donor, of potassium bromide or sodium bromide which are readily available commercially, is most advantageous for consumers. purposes of the present invention. The amount of substance providing bromine ions generally varies from 0.0001 to 0.5 moles, in particular 0.001 to 0.3 moles, per mole of the starting compound.

   If this amount of the substance providing bromine ions is smaller than that described above, the beneficial effect exerted by the bromine ion donor will not be obtained. On the other hand, if the amount of <EMI ID = 19.1>

  
of carboxylic acid will have to be increased in proportion in order to decrease the degree of selectivity towards intermediate oxidation products and, at the same time, the quantity of organobromine compounds formed as by-products will be greater,

  
thus resulting in the default that the cost of

  
the separation and purification of the desired product will be markedly increased. It is also important to limit the

  
quantity of substance providing bromine ions in proportion

  
of the amount of cobalt salt added. The amount of substance providing bromine ions is preferably limited to 0.001

  
to 10 moles, in particular 0.005 to 5 moles, per mole of the salt

  
cobalt. If the amount of the substance providing bromine ions is smaller than the above-mentioned range, the desired beneficial effect of adding the substance will not be obtained. On the other hand, if the quantity of substances providing bromine ions is higher than the aforementioned range, the reaction induction period will be markedly increased with a substantial decrease in the degree of selectivity towards the desired product. .

  
When carrying out the process according to the present invention, at least

  
a lower saturated fatty acid and / or at least one anhydride of

  
the latter functioning both as a reaction promoter and

  
of reaction solvent.

  
 <EMI ID = 20.1>

  
that it is used in the present specification, designates saturated aliphatic carboxylic acids having from 2 to 8 carbon atoms. As preferred examples of such lower saturated fatty acids, there may be mentioned acetic acid, propionic acid, n-butyric acid and isobutyric acid. The reaction solvents very particularly preferred for the implementation

  
of the process according to the present invention are acetic acid and acetic anhydride. Also included in the categories of lower saturated fatty acids which can be used for the purposes of the present invention are halogenated lower saturated fatty acids, that is to say lower saturated fatty acids with hampered halo substitution, such as chlorinated or brominated substitution. However, the use of such halogenated lower saturated fatty acids is less recommended.

  
 <EMI ID = 21.1> <EMI ID = 22.1>

  
process according to the present invention, besides the lower saturated fatty acid or an anhydride of the latter, it is also possible to use a reaction solvent which can be used for carrying out conventional oxidative reactions. As preferred examples of such an additional reaction solvent, there may be mentioned the hydrocarbons.

  
 <EMI ID = 23.1>

  
corresponding halogens. Besides these compounds, any organic solvent can be used, provided that it is inert to the oxidation reaction. The organic solvent which is inert to the oxidation reaction and which can replace part of the reaction solvent is used in an amount.

  
 <EMI ID = 24.1>

  
total reaction.

  
The catalyst used for carrying out the process according to the present invention consists of one or more soluble cobalt salts. In the reaction solvent, such a cobalt salt generates cobalt ions which then coordinate with the lower saturated fatty acid or an anhydride of the latter and then function as an effective catalyst for the synthesis of alcohols and aldehydes. When carrying out the process according to the present invention, it is also possible to use any of the soluble salts of cobalt, provided that they are soluble in the solvent and capable of generating, in the reaction liquid, a ligand consisting of by acid

  
lower saturated fat or anhydride of the latter, containing cobalt ions. As examples of suitable cobalt salts, there may be mentioned, for example inorganic cobalt salts,

  
such as cobalt chloride, cobalt bromide, hydroxide

  
of cobalt and cobalt nitrate and organic cobalt salts, such as cobalt acetate, cobalt propionate, cobalt stearate, cobalt naphthenate, cobalt acetylacetonate and cobalt benzoate. A cobalt halide cannot be considered as a preferable catalyst, since the reaction frequently does not take place by the use of such a cobalt halide alone. As is evident from the examples, however, the co-use of co- bromide

  
 <EMI ID = 25.1>

  
effects which are practically equivalent to those obtained in the case of the use of cobalt acetate together with bromide of <EMI ID = 26.1>

  
feel invention; cobalt halide as an effective catalyst, provided that it can be partially or totally replaced in the reaction system by the lower saturated fatty acid.

  
The amount of this solvent varies according to the type of solvent, according to the reaction conditions adopted and according to the type of compound to be oxidized, but generally fluctuates from 0.2 to 20 moles per mole of starting compound. A particularly preferable range of solvent amounts is from 2 to 15 moles per mole of the starting material. If the amount of solvent is too low,

  
the feature of the present invention will be lost, thus resulting in a considerable decrease in the reaction rate and a considerable decrease in the level of selectivity towards the desired products. and, in the extreme case,

  
the reaction frequently does not occur. On the other hand, the use of an excessive amount of solvent does not exert any significant influence on the oxidation reaction. In certain cases, the maximum degree of selectivity can be obtained by using a solvent in an amount of at least 15 moles per mole of the starting compound. However, the use of the solvent

  
Rather, in large excess results in the occurrence of various disadvantages including slowing down the rate of oxidation, reducing the productivity of desired products and increasing the optimum amount of catalyst and the cost of subsequent processing of the liquid reaction mass.

  
The optimum amount of catalyst varies depending on the reaction conditions used, the type of starting compounds, the solvents and the brominated compounds, the reaction temperature used and the type of solvent used, but this optimum amount is generally d at least 0.01 mole, preferably at least 0.01 mole per mole of the starting compound. The catalyst is advantageously used in an amount varying from 0.05%. 0.3 mole per mole of the starting compound. Therefore, the maximum amount of the catalyst can be regarded as the amount of catalyst corresponding to its saturation solubility in the reaction liquid under the adopted reaction conditions.

   If the amount of catalyst added is lower than the above range, both the reaction rate and the degree of selectivity towards the product <EMI ID = 27.1>

  
the amount of catalyst is too low. On the other hand, the use of the catalyst in an amount greater than the aforementioned range does not cause any appreciable negative effect with respect to the reaction except for the exertion of a certain influence on the reaction. technological aspect of the reaction. However, the use of an extremely excessive amount of the catalyst is undesirable for the reason that a large amount of the catalyst will be precipitated in the reaction liquid upon separation of the end product and thus decrease the yield of the desired product.

  
In order to produce substituted benzaldehydes and / or substituted benzyl alcohols in good yields, according to the process according to the present invention, it is essential to use a lower saturated fatty acid having from 2 to 8 carbon atoms and / or an anhydride. of the latter, as a solvent for carrying out the reaction. Acetic acid is particularly suitable as a lower saturated fatty acid and acetic anhydride is particularly suitable as a lower saturated fatty acid anhydride. The use of a mixture of acetic acid and acetic anhydride is effective for the oxidation of starting compounds which are difficult to oxidize, such as the meta-substituted compounds, under mild reaction conditions, using a relatively small amount of the catalyst.

  
(eg, using the catalyst in an amount not exceeding 0.05 mole per mole of the starting compound).

  
 <EMI ID = 28.1>

  
found that an improved result could be obtained by adding a co-oxidant as well as the substance providing bromine ions to the reaction system. In this case, the co-oxidant is defined as a substance capable of being easily oxidized under the reaction conditions in order to form a peroxy radical R'-O-Where R 'represents an organic residue. As examples of such a co-oxidant, mention may be made of aldehydes and ketones, such as acetaldehyde, paraldehyde, oyclohexanone and methyl ethyl ketone, as also n-butene. Considering the effect, the ease of handling, the price and the compounds formed by the oxidation of the co-oxidant, advantageously used are aldehydes and ketones, in particular acetaldehyde, paraldehyde and methyl ethyl ketone. From a processing point of view

  
 <EMI ID = 29.1> <EMI ID = 30.1>

  
sovant, while n-butyraldehyde is suitable when using n-butyric acid as a solvent. Therefore, suitable co-oxidants are not limited to the above mentioned three compounds.

  
The amount of the co-oxidant generally varies from 0.0001

  
 <EMI ID = 31.1>

  
tion of the co-oxidant will not be obtained. On the other hand, the use of an excessive amount of the oo-oxidant does not exert any particular influence on the oxidation reaction and is undesirable from the economic point of view as well as from the point of view of the prevention of any damage. difficulty in controlling the reaction, since the amount of heat generated during the reaction can become greater by the addition of a large amount of the 00-oxidant, The effect provided by the addition of the oo-oxidant is similar to that provided by the addition of the substance providing bromine ions and is effective in reducing the reaction temperature, shortening the reaction time and

  
 <EMI ID = 32.1>

  
intermediate dation sought. t As in the case of the addition of

  
 <EMI ID = 33.1>

  
tion of the 00-oxidant becomes remarkable for the oxidation of hardly oxidizable compounds. Without the case of compounds easily

  
 <EMI ID = 34.1>

  
 <EMI ID = 35.1>

  
in particular as regards the aspect formed by the cost of the oxidation of compounds which are difficult to oxidize. When carrying out the methods according to the present invention, the use

  
 <EMI ID = 36.1>

  
co-oxidant generates, during oxidation, acetic acid as an oxidation product. Similarly, the use of

  
 <EMI ID = 37.1>

  
propionic acid or n-butyric acid respectively. Therefore, a relatively large amount of such a co-oxidant allows the formation

  
a desired amount of saturated fatty acid less than

  
a relatively early stage of oxidation, even when the lower saturated fatty acid and / or its anhydride, are absent from the reaction system during the initiation of the reaction and this formation of the required amount of the lower saturated fatty acid thus serves to generate the desired intermediate oxidation product with a fairly good yield. This means that it is possible

  
to produce in the oxidation system the desired amount of lower saturated fatty acid in situ by first using a large amount of the co-oxidant. As the examples which follow demonstrate, this process is however disadvantageous from the economic point of view and is not preferable in the sense that the degree of selectivity towards the products of the intermediate oxidation is generally lower. at the level of selectivity obtained in the case of the addition of the lower saturated fatty acid and / or its anhydride, before or at the time of the initiation of the reaction. According to this method, the addition of the oo-oxidant in an amount

  
0.5 mole per mole of the starting compound is desirable, but the addition of such a large amount of co-oxidant requires the addition of an inert solvent serving as a diluent to allow moderation control of the reaction and makes the optimum reaction conditions relatively narrower.

  
The oxidative reactivity of the starting compounds used for the purposes of the present invention varies significantly depending on the position of attachment of the ether bond relative to the

  
 <EMI ID = 38.1>

  
cobalt, which thus minimizes the beneficial effect obtained by the addi- <EMI ID = 39.1>

  
quable the beneficial effect obtained by the addition of the bromine ion donor.

  
Regarding the use of the solvent, acetic acid

  
 <EMI ID = 40.1>

  
acetic, if the cobalt salt is added in a completely sufficient amount. It has been found that the use of the lower saturated fatty acid together with its anhydride in

  
 <EMI ID = 41.1>

  
lower, which does not occur in the case of the use of lower saturated fatty acid alone as solvent, taking into account

  
 <EMI ID = 42.1>

  
In order to obtain the desired intermediate oxidation products, such as alcohols and / or aldehydes, with a high yield and with a high selectivity, it is important, for the purposes of the present invention, to pay attention to the type of the starting compounds and the choice of the concrete reaction conditions suitable for the oxidation of the starting compounds in question.

  
During the implementation of the process of the present invention, the degree of conversion which will sometimes be referred to as the reaction rate is generally limited so that it does not exceed 90%. In accordance with the conforming process

  
to the present invention that the oxidation conditions are set so as to be very effective for the formation of intermediate oxidation products, such as alcohols and aldehydes, the oxidation reaction can be carried out at a conversion rate high to obtain the desired products. However, if the conversion rate exceeds 90%, the amount of byproducts formed will increase rapidly so as to concomitantly reduce the yield of final product. It is also important to adjust the optimum conversion rate to the kind of starting compound being used.

   For example, in the case where a toluene having an ether group in the meta position is oxidized so as to obtain the desired intermediate oxidation product with a high degree of selectivity, the degree of conversion must be limited to 60% and less, preferably 15-50%, as will be apparent from the data of the examples which follow. The minimum value of the conversion rate is generally limited to at least 10%, considering the economic aspect and the process. Depending on the type of final product or depending on the commercial value of the final product there is however a case where the process is still economically attractive even at a lower conversion rate, for example a conversion rate as low as 5 to
10%. Therefore, the lower limit of the conversion rate

  
is not restricted to the value specified above. Unlike the case of the oxidation of a starting compound having a

  
 <EMI ID = 43.1>

  
Otherwise, the desired intermediate oxidation product is not obtained with a high degree of selectivity. The reason for this phenomenon is not yet clear until now. However, this phenomenon apparently seems to be observed regardless of the species of

  
 <EMI ID = 44.1>

  
oxidation of toluene substituted in the ortho position or in the para position. More precisely, the relation existing between the conversion rate and the degree of selectivity towards the final product can be explained as follows: when

  
 <EMI ID = 45.1>

  
the degree of selectivity towards the aldehyde in the case of the oxidation of toluene substituted in the ortho position was 58,
62, 73 and 75, respectively, expressed in mol%, the degree of selectivity towards the aldehyde in the case of the oxidation of the toluene substituted in the para position was 65, 63, 61 and 71, respectively expressed in mol% and the degree of selectivity

  
 <EMI ID = 46.1>

  
substituted in meta position was only 16, 38, 70 and
67, respectively, expressed in mol%, which thus shows that the degree of selectivity towards the aldehyde in the case

  
 <EMI ID = 47.1>

  
quickly when the conversion rate exceeds 50%. A similar phenomenon was also observed, when we obtained

  
 <EMI ID = 48.1>

  
it was possible to obtain the corresponding aldehydes with a degree of

  
 <EMI ID = 49.1>

  
from 50 to 80%, by the choice of suitable reaction conditions. In the case of the oxidation of toluene substituted in position

  
 <EMI ID = 50.1>

  
difficult to increase the degree of selectivity towards the intermediate oxidation compound to at least 40 mol%, regardless of the reaction conditions adopted at a rate of

  
 <EMI ID = 51.1>

  
60% and above, it was difficult to maintain the degree

  
 <EMI ID = 52.1>

  
oxidation for the purpose of obtaining a mixture of an alcohol and an aldehyde, the relationship between the conversion rate and the degree of selectivity showed the same tendency as that described in the case cited above. Therefore, it is evident that when an ether group is present in the meta position relative to the group

  
 <EMI ID = 53.1>

  
desired cannot be obtained with a high degree of selectivity when the conversion rate is maintained at 60% and above. In the case of toluenes substituted in the or tho and para postions, it is also desirable to adjust the conversion rate appropriately to production with good yields of the desired intermediate oxidation products. In the case of compounds substituted in the ortho position, for example, advantageously limited

  
 <EMI ID = 54.1>

  
In the case of compounds substituted in the para position, it is advantageous to limit the degree of conversion to at most 90%, preferably

  
 <EMI ID = 55.1>

  
When the reaction is carried out using toluenes substituted in the meta position as starting materials, the reaction temperature varies greatly depending on the presence or absence of a co-oxidant. In the case of absence

  
of a co-oxidant, the reaction temperature varies from 50 to 180 [deg.] C, from

  
 <EMI ID = 56.1>

  
toluenes substituted in the meta position is usually at least 0.01 mole per mole of the starting compounds. When the oxygen pressure rises in the oxidation reaction, for example, when the partial pressure of oxygen is raised to at least 2 kg / cm3, the catalytically effective minimum amount of the catalyst is reduced to to 0.001 mole per mole of the starting compounds.

  
Since toluenes substituted in the orto and para positions are more easily oxidized than toluenes substituted in the meta position, the reaction temperature can vary within wide limits but generally fluctuates from 30 to 180 [deg.] C. The minimum catalytically effective amount of the catalyst in this case is at least 0.001 mole per mole of the starting compounds.

  
When starting compounds having two ether groups are subjected to the oxidation reaction, the above-mentioned tendency is also manifested depending on the relative positions of the ether groups with respect to the methyla group. The reaction temperature adopted in this case fluctuates from 40 to 200 [deg.] C and the minimum catalytically effective amount of the catalyst is preferably at least 0.001 mole per mole of the starting materials.

  
In accordance with the present invention, the compounds of

  
 <EMI ID = 57.1>

  
hyde) is present in place of the methyla group. In this case, the reaction, carried out under a low oxygen pressure of 0.1 to

  
 <EMI ID = 58.1>

  
under high oxygen pressure by the composition of the reaction liquid and by the optimum composition of the reaction liquid. In order to obtain the final product in a high yield, it is necessary to choose the reaction conditions appropriately, including the reaction temperature, the composition of the solvent, the amount of catalyst and the like. In this

  
which concerns the solvent, for example, it is advantageous to use a mixed solvent comprising the lower saturated fatty acid

  
and an anhydride thereof when an oxygen pressure as low as 0.1 to 2 kg / cm2 is used for the purposes of the present invention. The use of such a mixed solvent makes it possible to obtain

  
a high conversion rate and a high degree of selectivity with respect to the final product. With regard to the catalyst,

  
it is necessary to use it in an amount of at least 0.01 mole per mole of the starting compound to be oxidized. On the other hand, if the oxygen pressure is high, the reaction proceeds smoothly

  
in comparison with the case of working under low oxygen pressure. Therefore, in this case, the limitations imposed

  
the composition of the solvent, the amount of the catalyst and the like are less stringent than when low oxygen pressure is used.

  
By the term "molecular oxygen" as used herein and the claims which conclude it is meant to define, in addition to oxygen itself, various types of oxygen-containing gases such as air and a mixture of air and oxygen.

  
The oxidation reaction can be carried out as a batch operation or a continuous operation and the mode of operation, batch or continuous, can conveniently be determined by taking into consideration the productivity, cost and the like. .

  
The separation and recovery of the end product, catalyst, solvent and starting material from the liquid reaction mixture can be accomplished by a process known per se to those skilled in the art. For example, the final product can be easily isolated with a high yield of the liquid reaction mixture, by removing the majority of the lower saturated fatty acid remaining in the reaction liquid, by distillation under reduced pressure, addition of toluene and water to the reaction mixture. distillation residue, separation of an aqueous paste containing the catalyst and lower saturated fatty acid in solution, from a toluene phase containing the starting material and the end product and subsequent distillation of the toluene phase at a pressure below atmospheric pressure.

   It is obvious that the solvent and the catalyst recovered in this way can again be used for a further reaction of this type.

  
The present invention will now be illustrated in more detail with the aid of various examples. In the tables relating to

  
 <EMI ID = 59.1>

  
Acetic ester "are used to denote the compounds corresponding to the starting compounds used.

  
 <EMI ID = 60.1>

  
 <EMI ID = 61.1>

  
with a capacity of 500 ml, equipped with a stirrer, a thermometer, a gas inlet tube, a reflux condenser and a gas outlet tube, 200 ml of 'a liquid starting mixture, consisting of m-phenoxytoluene, acetic acid, acetic anhydride, cobalt acetate tetrahydrate and a bromine compound in a proportion of

  
 <EMI ID = 62.1>

  
mixture in an oil bath and the reaction temperature was maintained at a given value. We then introduced a

  
 <EMI ID = 63.1>

  
that the latter was vigorously shaken at a speed of

  
 <EMI ID = 64.1>

  
 <EMI ID = 65.1>

  
liquid reaction with honey carried out by chromatography in

  
 <EMI ID = 66.1>

  
benayle formed Appear in table 1.braque on

  
 <EMI ID = 67.1>

  
 <EMI ID = 68.1> EXAMPLE 2

  
Using cobalt acetate as the cobalt salt, lithium bromide (sodium bromide in the experiments with white circle) as the bromine compound and a mixture of acetic acid and acetic anhydride as a solvent, it was achieved the oxidation treatment of m-phenoxytoluene to

  
normal pressure, under various reaction conditions. The results obtained appear in Table 2 below.

  
The process used for carrying out the experiments and

  
the method for product analysis were identical to those described in Example 1.

  
EXAMPLE 3

  
Except that m-methoxytoluene was used as the starting material to be oxidized, the experiments of

  
the same way as those described in example 2, so

  
that the results shown in Table 3 were obtained. In these experiments, NaBr was used as the brominated compound and oxygen (flow rate: 3.0 - 3.6 liters / h) as the oxidizing agent. The synthesis of m-methoxytoluene was carried out by methylating

  
m-cresol with dimethyl sulfate in a usual manner and was completely purified in the same manner as described in Example 1 before use. In Table 3, experiments n [deg.] 15-20 represent results of comparative examples.

  
EXAMPLE 4

  
In the same manner as that described in Example 3, various compounds were oxidized with oxygen. When a comparison was made between the case where a brominated compound

  
was present in the reaction system and the case where a

  
tal bromine compound was absent from the reaction system, it was found that in the case of the absence of the bromine compound it

  
reaction did not occur under the reaction conditions shown in Table 4. The results of the experiments where the reaction took place are shown in Table 4.

  
table 4 below.

  
EXAMPLE 5

  
In a four-necked flask, Pyrex glass, with a capacity of 500 ml, equipped with a stirrer, a thermometer, a gas inlet tube, a reflux condenser and a gas outlet tube, 200 ml were introduced

  
 <EMI ID = 69.1>

  
then introduced a stream of air at a rate of 300 ml / min

  
into the mixture, while stirring vigorously at low speed

  
rotation of 1000-1200 rpm. The reaction was carried out for

  
period of time and the product of the

  
same way as that described in example 1. The results

  
of the experiments are shown in Table 5. In the case where

  
no co-oxidant was added, the mixture did not react at all, even when the bromine compound was added,

  
 <EMI ID = 70.1>

  
Using NaBr as the bromine compound, the marl oxidation experiment was carried out in a manner as described in Example 5, in order to study the relationship between the reaction temperature and the results of the reaction. The results of the experiments in question are shown in Table 6.

  
EXAMPLE 7

  
Using cobalt acetate tetrahydrate

  
 <EMI ID = 71.1>

  
normal pressure, under various reaction conditions,

  
 <EMI ID = 72.1>

  
reaction and product analysis method were identical

  
 <EMI ID = 73.1>

  
as a starting material and this starting material was prepared according to the usual method by reacting m-cresol with dimethyl sulfate and sufficiently purified before use.

  
EXAMPLE 8

  
With the exception of the fact that the starting material

  
to be oxidized was m-phenoxytoluene, this experiment was carried out in the same way as that described in Example 7,

  
the results obtained being represented in table 8

  
following.

  
EXAMPLE 9

  
The experiment for the oxidation of various compounds with oxygen was carried out in the same manner as that described in Example 5, in order to compare the case where the presence of a brominated compound was allowed and of a co-oxidant in the reaction system and the case where the presence of these ingredients in the reaction system has not been tolerated. In the event that the brominated compound and the co-oxidant were absent

  
of the reaction system, the reaction did not take place under the reaction conditions shown in Table 9 and still did not take place within 3 hours, even in the case of raising the reaction temperature to about the boiling point of acetic acid and the use, as solvent, of a mixture of 2-3 molar proportions of acetic anhydride and 8-10 molar proportions of acetic acid, based on the compound starting point.

  
The results of the experiments obtained in the case where the presence of the co-oxidant and of the bromine compound were allowed in the reaction system, are collated in Table 9.

  
The starting material was prepared in the usual manner

  
from m-cresol and a bromohydrocarbon. The product

  
of the reaction was identified by the CG-SM method.

  
EXAMPLE 10

  
In a four-necked flask, in Pyrex glass, with a capacity of 500 ml, equipped with a stirrer, a thermometer, a gas inlet tube, a reflux condenser and a gas outlet tube, 200 ml of a liquid starting mixture consisting of o-methoxytoluene, acetic acid, cobalt acetate tetrahydrate and a bromine compound were introduced in a proportion of 1: 8: 0.1: 0.01 (molar ratio). This mixture was maintained in a water bath at a reaction temperature of
60-65 [deg.] C and a stream of oxygen was introduced at a rate of 3.6 liters / hr into the mixture while stirring vigorously at a rotational speed of 1000 rpm. The reaction was carried out for a given period of time. The reaction product was analyzed in the same manner as described in Example 1.

   The results of these experiments are shown in Table 10. When no brominated compound was added, the reaction did not proceed under the above conditions. We proceeded

  
to the synthesis of the starting o-methoxytoluene by carrying out a usual process by reacting o-cresol with dimethyl sulfate and the material has been sufficiently purified

  
starting before use by repeated washing with an alkali

  
and distillation.

  
EXAMPLE 11

  
Using NaBr as the brominated compound, the oxidation experiment was carried out in the same manner as that described in Example 10, in order to investigate the influence of the reaction temperature and the conversion rate on the result of the reaction. 'experience. Table 11 shows the results thus obtained.

  
EXAMPLE 12

  
Using acetic acid as a solvent and both cobalt acetate tetrahydrate and NaBr as a catalyst, the experiment for the oxidation of o-methoxytoluene with oxygen, at normal pressure, was carried out. in the same manner as that described in Example 10, in order to examine the amounts of acetic acid, Co and NaBr, as also the effect of the addition of acetaldehyde. The results obtained appear in Table 12 below.

  
EXAMPLE 13

  
Except that the starting material to be oxidized consisted of p-methoxytoluene, the experiments were carried out

  
in the same manner as that described in Example 12, in order to obtain the results shown in Table 13. During the performance of these experiments, commercial p-methoxytoluene was sufficiently purified in the same manner as that described in Example 10, before using this compound.

  
EXAMPLE 14

  
Using acetic acid as a solvent and cobalt acetate tetrahydrate as a catalyst, experiments on the oxidation of various compounds with oxygen, at normal pressure, were carried out in order to make a comparison of the case. where a bromine compound was present in the reaction system or where a bromine compound and a co-oxidant coexisted in the reaction system, in the event that a bromine compound alone or used in conjunction with a co-oxidant was absent from the reaction system. The results obtained appear in the table

  
14. The starting material was synthesized by reacting p-cresol with a bromohydrocarbon, in the presence of a caustic alkali serving as a condensing agent, according to the usual method and sufficiently purified in the same manner as that described in Example 10. before using it. The reaction product was identified by carrying out the process

  
 <EMI ID = 74.1>

  
EXAMPLE 15

  
In an autoclave made of SUS-316 stainless steel, with a capacity of 300 ml, equipped with a stirrer, a thermometer and a gas inlet tube, 150 ml of the liquid starting mixture having a given composition.

  
heated the mixture to a given temperature, while vigorously stirring this mixture at a rotational speed of
1600 rpm. From a pressurized tank, oxygen was introduced into the mixture via a pressure regulator so as to maintain the oxygen pressure at

  
1.5 kg / cm <2> (absolute pressure). The amount of oxygen consumed was roughly calculated from the decrease in oxygen pressure in the pressure vessel and the reaction was stopped by rapidly cooling the reactor as a given amount of oxygen was absorbed into the pressure vessel. starting material. The reaction product was analyzed

  
in the same manner as that described in Example 1. The results of these experiments appear in Table 15 which follows. EXAMPLE 16

  
Using p-n-octyloxytoluene as the starting material, AcOH as a solvent, NaBr as the brominated compound and cobalt acetate tetrahydrate as the cobalt salt, one can

  
carried out the experiments in the same way as described

  
in Example 10. The results of these experiments are shown in Table 16 below.

  
EXAMPLE 17

  
In a SUS-316 stainless steel autoclave, with a capacity of 300 ml, equipped with a stirrer, a thermometer and a gas inlet tube, 30 g of m-phenoxytoluene, 120 g of acetic acid, 12 g of cobalt acetate tetrahydrate and various bromine compounds in an amount

  
 <EMI ID = 75.1>

  
the liquid mixture to a given temperature and then a stream of oxygen was introduced from a pressure tank through a pressure regulator into

  
mixing while stirring vigorously at a rotational speed of 1600 rpm. The internal pressure of oxygen was maintained at 20 kg / cm <2>. As soon as the oxygen gas was introduced or after a short induction period had taken place, a violent oxidation reaction took place, so that it was difficult to keep the reaction temperature within well-defined limits. However, we paid attention

  
especially in keeping the reaction temperature within limits as defined as possible by heating or

  
by cooling and the amount of oxygen consumed was roughly calculated from the decrease in oxygen pressure in the pressurized oxygen tank. By the time substantially the required amount of oxygen had been absorbed, the reactor was quickly cooled to stop the reaction. The reaction product was analyzed in a manner similar to that described in Example 1. The results obtained appear in Table 17 which follows.

  
EXAMPLE 18

  
Using NaBr as the bromine compound, the experiments were carried out so as to investigate the influence

  
of the amount of NaBr added to the results. Table 18 shows the results obtained. With the exception of the amount of NaBr added, the reaction conditions adopted in this example were quite the same as those adopted in example 17.

  
EXAMPLE 19

  
With the exception of the variation in the ratio of Co to NaBr, the experiments were carried out in the same manner as that described in Example 18. The results obtained are presented in Table 19. The majority of the data in this Table 19 correspond to the data in Table 6 shown in terms of the ratio of Co to added NaBr.

  
EXAMPLE 20

  
Except that the bromine compound was NaBr and the amount of Co salt was varied, the experiments were carried out in the same manner as described in Example 17, in order to find the influence of the amount of cobalt salt. The results obtained appear in Table 20 which follows.

  
EXAMPLE 21

  
Experiments were carried out under such a condition that the mixing ratio of m-phenoxytoluene to acetic acid was varied. Using as catalysts

  
3 mol% of cobalt acetate tetrahydrate and 3 mol%

  
 <EMI ID = 76.1>

  
limiting the total volume of the reaction liquid to 150 ml, the experiments were carried out in the same manner as that described in Example 17. The results obtained appear in Table 21. No substantial amount of product d was obtained. intermediate oxidation when the amount of acetic acid was zero. When the amount of acetic acid was 0.5 mole per mole of m-phenoxytoluene, m-phenoxybenzaldehyde was obtained with a rate or degree of selectivity

  
 <EMI ID = 77.1>

  
this experiment showed poor reproducibility, EXAMPLE 22

  
With the exception of the fact that the oxygen pressure was varied and that the bromine compound consisted entirely of NaBr, the experiments in question were carried out under the same conditions as those described in Example 17 '.

  
 <EMI ID = 78.1>

  
following.

  
EXAMPLE 24

  
 <EMI ID = 79.1>

  
repeated experiments 23 in order to investigate the influence of the reaction temperature. The results obtained appear in Table 24,

  
EXAMPLE 25

  
 <EMI ID = 80.1> 12.5 moles per mole of starting compound and cobalt acetate tetrahydrate in an amount of 0.3 moles per mole of starting compound, in the presence or absence of sodium bromide , under an oxygen pressure of 20 kg / cm <2>. The results obtained appear in Table 26.

  
The starting compound was prepared in the same manner as described in Example 17, starting from o-, m- or p-cresol and a bromohydrocarbon. The identification of the reaction product was carried out according to the CG-MS method.

  
EXAMPLE 27

  
Except that sodium bromide was used as the brominated compound, various cobalt salts were added in an amount of 0.1 mole per mole of starting compound, and the oxygen pressure was 7 kg. / cm <2>, the oxidation reactions of o- and p-phenoxytoluenes were carried out in the same manner as that described in Example 17. The results obtained appear in Tables 27 (a) and 27 (b) .

  
EXAMPLE 28

  
In a four-necked flask, in Pyrex glass, with a capacity of 500 ml, equipped with a stirrer, a thermometer, a gas inlet tube, a reflux condenser and a gas outlet tube, 150 ml of a liquid starting mixture composed of 3,4-dimethoxytoluene, acetic acid, cobalt acetate tetrahydrate, a compound of bromine and paraldehyde were introduced in a proportion from 1: 12.5: 0.3: 0.03: 0.05
(molar ratio). The mixture was kept in a hot water bath at a temperature of 70-80 [deg.] C and a stream of oxygen was introduced at a rate of 3.6 liters / hr into the mixture while stirring. vigorously at a rotational speed of
1000-1200 rpm. The reaction was carried out for a given period of time.

   The reaction liquid was analyzed by gas chromatography at elevated temperatures using a silane-treated Chromosolve feed bearing 7% by weight of OV-17 silicone oil. The results of the experiments are shown in Table 28 below. The

  
 <EMI ID = 81.1>

  
the starting product by boiling the crude product with

  
 <EMI ID = 82.1> 3 hours, washing the product with water, distilling

  
the product under reduced pressure, washing the distillate first

  
 <EMI ID = 83.1>

  
thoroughly with water, distilling the product under reduced pressure and then drying the distillate with calcium chloride.

  
EXAMPLE 29

  
With the exception of the use of sodium bromide as the bromine compound and except that the reaction conditions were varied with respect to the amount of paraldehyde and the reaction temperature, the reaction of oxidation of 3,4-diethoxytoluene with oxygen, under normal pressure, in the same manner as that described in Example 28. The results obtained are shown in Table 29. 3,4-diethoxytoluene was prepared used as starting material by carrying out a usual process, by O-ethylation of homocatechol with diethyl sulfate and the starting product was completely purified by repeating the procedure described in Example 28 .

  
EXAMPLE 30

  
Except that sodium bromide was used as the brominated compound, the oxidation of the various compounds with oxygen was carried out in the same manner as described in Example 28. results obtained appear in Table 30. The starting compounds shown were prepared.

  
 <EMI ID = 84.1>

  
As the starting material, commercially available dihydroxytoluene and methylated or ethylated in the same manner as described in Example 28. The propylation or

  
butylation of the starting material according to a usual process

  
by heating this starting material and propyl bromide or butyl bromide as well as potassium hydroxide, in an amount of 3 moles per mole of the starting material and a small amount of powdered copper. The compounds thus obtained were sufficiently purified before their use of the

  
same manner as that described in Example 28.

  
EXAMPLE 31

  
Into a SUS-316 stainless steel autoclave, with a capacity of 300 ml, equipped with a stirrer, a thermometer and a gas inlet tube, a total quantity of 150 ml of quantities was introduced. data for 3,4-diethoxytoluene, cobalt acetate tetrahydrate, acetic acid, sodium bromide and paraldehyde. The liquid mixture was heated to a predetermined temperature, while being stirred vigorously at a rotational speed of 1600 rpm. From a pressurized oxygen reservoir, pressurized oxygen was introduced into the autoclave via a pressure regulator, so as to maintain the pressure at a given value. As soon as we have introduced gaseous oxygen,

  
a violent oxidation reaction took place, so that it was difficult to maintain the reaction temperature at a defined value. However, special care has been taken to maintain the reaction temperature between

  
limits as defined as possible by heating or cooling and the amount of oxygen consumed was roughly calculated from the decrease in pressure

  
oxygen in the pressurized oxygen tank. Upon absorption of an amount of oxygen corresponding to substantially the amount of oxygen required, the reactor was rapidly cooled to stop the reaction. The reaction liquid was analyzed in the same manner as described in Example 28. The results obtained are presented in Table 31 in which the reaction temperature appears under predetermined value and maximum value. EXAMPLE 32

  
Various dihydrocarbyloxytoluenes were subjected to pressurized liquid phase oxidation and these oxidations were carried out in the same manner as described in Example 31. The results obtained appear in Table 32. In

  
this example, the starting mixture used for the implementation of each experiment had the following composition:
starting compound: acetic acid: cobalt acetate tetrahydrate: sodium bromide = 1: 12.5: 0.3: 0.03 (molar ratio). The starting compounds used in

  
this example in the same way as that described in Example 30.

  
EXAMPLE 33

  
In order to investigate the effect of paraldehyde, 3,4-dimethoxytoluene was subjected to oxidation under normal pressure in the presence of cobalt acetate tetrahydrate and paraldehyde, but in the absence of a brominated compound, of the same. manner as that described in Example 28. The results obtained appear in Table 33 which follows. In this example, the starting mixture used for carrying out each experiment had the following composition:
3,4-Dimethoxytoluene: acetic acid: cobalt acetate tetrahydrate = 1: 12.5: 0.3 (molar ratio).

  
Table 1
 <EMI ID = 85.1>
 Notes:

  
* 1 The composition of the liquid starting mixture was

  
next :

  
 <EMI ID = 86.1>

  
1: 7: 0.02: 0.1 (expressed as a molar ratio). The bromine (Br2) in the reaction system was partially converted easily into an organobromine compound and HBr.

  
* 2 A reagent available in the

  
trade of special quality (purity: aqueous solution at 47 - 48 Si).

  
* 3 The composition of the liquid starting mixture was

  
next :

  
Starting material: acetic acid: NaBr: Co = 1: 8: 0.01: 0.1 (molar ratios). The oxidation was carried out with oxygen for 1 hour (flow rate: 3.6 l / h).

  
* 4 Oxygen was used as the oxidizing agent (flow rate:

  
3.6 l / h) and the reaction time was one hour.

  
* 5 The composition of the liquid starting mixture was

  
next :

  
Starting material: acetic acid: acetic anhydride:

  
 <EMI ID = 87.1>

  
reaction was 6 hours.

  

 <EMI ID = 88.1>


  

 <EMI ID = 89.1>
 

  

 <EMI ID = 90.1>


  

 <EMI ID = 91.1>
 

  
Notes:

  
Oxygen was used as an oxidizing agent in

  
 <EMI ID = 92.1>

  
* 1 Propionic acid was used instead of acid

  
acetic.

  
* 2 Cobalt acetylacetonate (bivalent) was used

  
instead of cobalt acetate tetrahydrate.

  
* 3 Oxygen (3.6 l / h) was used as oxidizing agent

  
instead of air,

  
* 4 Cobalt benzoate was used instead of acetate

  
 <EMI ID = 93.1>

  
* 6 Propionate,

  
 <EMI ID = 94.1>

  
cobalt acetate tetrahydrate and sodium acetate was added in a 0.2 molar proportion with respect to

  
 <EMI ID = 95.1>

  
cobalt and sodium acetate, cobalt acetate

  
 <EMI ID = 96.1>

  
than that obtained in the case of the addition of cobalt acetate and aodium bromide,

  
 <EMI ID = 97.1>

  

 <EMI ID = 98.1>


  

 <EMI ID = 99.1>
 

  

 <EMI ID = 100.1>


  

 <EMI ID = 101.1>
 

  
Notes:

  
* 1 Cobalt nitrate hexahydrate was used instead of

  
cobalt acetate tetrahydrate.

  
* 2 Cobalt naphthenate was used (cobalt content:

  
10% by weight) instead of cobalt acetate. tetrahydrate.

  
* 3 KBr was used instead of NaBr.

  
* 4 Air (flow rate: 300 ml / min) was used as the agent

  
oxidant.

  
* 5 n-butyric acid was used instead of acid

  
acetic.

  
* 6 Cobalt acetylacetonate (bivalent) was used

  
instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 102.1>

  
* 8 In addition to cobalt acetate tetrahydrate, we added

  
0.01 molar proportion of nickel acetate tetrahydrate and 0.005 molar proportion of cerium acetate monohydrate, based on the starting material.

  
Although the presence of very small amounts of nickel ions and cerium ions was tolerated at the same time as that of cobalt ions, as can be seen in this experiment, the result of the reaction was somewhat better. , but the speed was not so great and was only equivalent to the best result obtained in the case of the use of cobalt alone.

  
 <EMI ID = 103.1>

  
0.03 molar proportion of manganese acetate based on the starting material. In this case, the reaction result was slightly better than in the case of

  
 <EMI ID = 104.1>

  
was also found in the case of the addition of a very small amount of chromium ions.

  

 <EMI ID = 105.1>


  

 <EMI ID = 106.1>
 

  
 <EMI ID = 107.1>

  
* 1 The starting compounds were represented by the formula

  
of the following general structure:

  

 <EMI ID = 108.1>


  
* 2 Molar ratio vis-à-vis the starting compounds.

  
 <EMI ID = 109.1>

  
acetic.

  
* 4 Air (flow rate: 300 ml / min) was used as the agent

  
oxidizer instead of oxygen.

  
* 5 The experiment was carried out using an autoclave in

  
SUS-316 stainless steel with a capacity of 400 ml, equipped with a stirrer, a thermometer and a gas inlet tube and the oxidation of the starting material with oxygen was carried out under a pressure of

  
 <EMI ID = 110.1>

  
from a pressure tank via a pressure regulator and the oxygen pressure was maintained at all times at 1.5 kg / cm <2>.

  
The stirring speed was 1600 rpm.

  
 <EMI ID = 111.1>

  
Table 5
 <EMI ID = 112.1>
  <EMI ID = 113.1>

  
Table 6
 <EMI ID = 114.1>
 Notes:

  
 <EMI ID = 115.1>

  
m-phenoxytoluene: acetic acid: cobalt acetate

  
 <EMI ID = 116.1>

  
(ratio + molar). Oxygen was used (flow rate:
3, 6 liters / h) as an oxidizer.

  
* 2 The composition of the reaction liquid was as follows:

  
m-phenoxytoluene: acetic acid: cobalt acetate tetrahydrate: NaBr: acetaldehyde - 1: 8: 0.01: 0.01: 0.03
(molar ratio). Oxygen (flow rate: 3.6 liters / h) was used as the oxidizing agent.

  
* 3 The composition of the reaction liquid was as follows:

  
m-phenoxytoluene: acetic acid: acetic anhydride:

  
 <EMI ID = 117.1>

  
= 1: 7: 0.5: 0.1: 0.07: 0.03 (molar ratio).

  
* 4 The composition of the reaction liquid was as follows:

  
m-phenoxytoluene: acetic acid: acetic anhydride:
cobalt acetate tetrahydrate: LiBr.H20: acetaldehyde

  
 <EMI ID = 118.1>

  

 <EMI ID = 119.1>


  

 <EMI ID = 120.1>
 

  

 <EMI ID = 121.1>


  

 <EMI ID = 122.1>
 

  
Notes:

  
\ j

  
 <EMI ID = 123.1>

  
(acetaldehyde).

  
* 2 Cobalt benzoate was used instead of sodium acetate.

  
cobalt tetrahydrate.

  
 <EMI ID = 124.1>

  
 <EMI ID = 125.1>

  
10% by weight) instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 126.1>

  
added was insoluble in the reaction liquid at the reaction temperature.

  
 <EMI ID = 127.1>

  
tetrahydrate was insoluble in the reaction liquid

  
at the start of the reaction but was almost completely dissolved in the reaction liquid at the end of the reaction, possibly due to the reaction of forming acetic acid by oxidation of the co-oxidant.

  
 <EMI ID = 128.1>

  
a 0.01 molar proportion of nickel acetate tetrahydrate based on the starting m-methoxytoluene. This experiment clearly shows that when one tolerates the presence of a very small quantity of nickel ions in coexistence with cobalt ions, the result obtained is sometimes better but that the rate is not so high and is only equivalent to the best result obtained in the case of using the cobalt salt alone under optimal conditions (the result of experiment n [deg.] 3 in Table 5 above). Only a poor result was obtained by adding nickel ions alone.

  
This characteristic clearly shows that the main catalytic effect is obtained by the active unit formed by the Co-Br system.

  
* 10 In addition to the cobalt acetate tetrahydrate, we added

  
a 0.01 molar proportion of nickel acetate tetrahydrate and a 0.005 molar proportion of cerium acetate monohydrate, based on the starting m-methoxytoluene.

  
During this experiment, the result seemed somewhat better. Such a degree of improvement in the result has also been obtained in the case of the addition of a very small amount of chromium ions or manganese ions.

  

 <EMI ID = 129.1>


  

 <EMI ID = 130.1>
 

  
Notes:

  
* 1 Paraldehyde was used instead of AcH and used

  
air as an oxidizing agent.

  
* 2 Cobalt stearate was used instead of acetate

  
cobalt tetrahydrate.

  
* 3 Propionic acid was used instead of acid

  
acetic.

  
* 4 Cobalt nitrate hexahydrate was used instead

  
cobalt acetate tetrahydrate.

  
* 5 Cobalt acetylacetonate (bivalent) was used

  
instead of cobalt acetate tetrahydrate.

  
* 6 KBr was used instead of NaBr.

  
* 7 Methyl ethyl ketone was used instead of AcH.

  
* 8 Propionate.

  
* 9 Cobalt hydroxide was used (cobalt content:

  
60% by weight) instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 131.1>

  
cobalt acetate tetrahydrate and a 0.2 molar proportion of sodium acetate based on the starting m-phenoxytoluene was used. When cobalt bromide was added along with sodium acetate as can be seen in this experiment,

  
it was assumed that these compounds were easily converted into cobalt acetate and sodium bromide, so that the same effect was obtained as the effect obtained in the case of the addition of cobalt acetate tetrahydrate and sodium bromide.

  

 <EMI ID = 132.1>


  

 <EMI ID = 133.1>
 

  
Notes:

  
* 1 The starting compounds were represented by the formula

  
of the following general structure:

  

 <EMI ID = 134.1>


  
 <EMI ID = 135.1>

  
* 3 Paraldehyde.

  
 <EMI ID = 136.1>

  
* 5 n-Butyric acid was used in this experiment

  
instead of acetic acid.

  
* 6 In this experiment, the oxidation of the

  
starting compound with oxygen at oxygen pressure

  
 <EMI ID = 137.1>

  
400ml SUS-316 stainless steel autoclave, equipped with stirrer, thermometer and gas inlet tube. In this case, oxygen was supplied

  
from a pressure tank through a pressure regulator and the oxygen pressure was maintained at all times at 1.5 kg / cm <2>. The stirring speed was 1600 rpm.

  

 <EMI ID = 138.1>


  

 <EMI ID = 139.1>
 

  
Table 11

  

 <EMI ID = 140.1>


  
Notes:

  
* A 0.03 molar proportion of acetaldehyde was added to

  
 <EMI ID = 141.1>

  

 <EMI ID = 142.1>


  

 <EMI ID = 143.1>
 

  

 <EMI ID = 144.1>


  

 <EMI ID = 145.1>
 

  
 <EMI ID = 146.1>

  
 <EMI ID = 147.1>

  
* 2 Cobalt benzoate was used instead of sodium acetate.

  
cobalt tetrahydrate.

  
* 3 Air (flow rate: 300 ml / min) was used as the agent

  
oxidizer instead of oxygen.

  
 <EMI ID = 148.1>

  
* 6 KBr was used instead of NaBr.

  
* 7 Cobalt acetylacetonate (divalent) was used in

  
instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 149.1>

  
cobalt tetrahydrate.

  
 <EMI ID = 150.1>

  
cobalt acetate tetrahydrate.

  
 <EMI ID = 151.1>

  

 <EMI ID = 152.1>


  

 <EMI ID = 153.1>
 

  

 <EMI ID = 154.1>


  

 <EMI ID = 155.1>
 

  
Notes:

  
 <EMI ID = 156.1>

  
* 2 n-Butyric acid was used instead of AcOH.

  
* 3 Methyl ethyl ketone was used instead of AcH.

  
* 4 Cobalt naphthenate was used (cobalt content:

  
10% by weight) instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 157.1>

  
oxidizer instead of oxygen.

  
* 6 Cobalt nitrate hexahydrate was used instead

  
cobalt acetate tetrahydrate.

  
 <EMI ID = 158.1>

  
(bivalent) as a catalyst instead of cobalt acetate tetrahydrate. In the experiments according to the present invention, the formation of aldehyde was recognized probably due to the fact that acetic acid was formed in situ from paraldehyde. In the Reference Examples, aldehyde formation was not recognized probably due to the fact that lower fatty acids were not formed in situ.

  

 <EMI ID = 159.1>


  

 <EMI ID = 160.1>
 

  

 <EMI ID = 161.1>


  

 <EMI ID = 162.1>
 

  

 <EMI ID = 163.1>


  

 <EMI ID = 164.1>


  

 <EMI ID = 165.1>
 

  

 <EMI ID = 166.1>


  

 <EMI ID = 167.1>


  

 <EMI ID = 168.1>
 

  
Table 17
 <EMI ID = 169.1>
 Notes:

  
* 1 Maximum and minimum temperatures have been given during

  
of the reaction.

  
* 2 A commercially available reagent was used

  
special grade (47-48% purity aqueous solution) as is.

  
* 3 The reaction did not occur until the

  
raised the temperature up to that temperature.

  
* 4 The reaction will not start below this

  
temperature. This experiment was carried out at an oxygen pressure of 45 kg / cm.

  

 <EMI ID = 170.1>


  

 <EMI ID = 171.1>


  

 <EMI ID = 172.1>
 

  

 <EMI ID = 173.1>


  

 <EMI ID = 174.1>


  

 <EMI ID = 175.1>
 

  

 <EMI ID = 176.1>


  

 <EMI ID = 177.1>


  

 <EMI ID = 178.1>
 

  

 <EMI ID = 179.1>


  

 <EMI ID = 180.1>
 

  
Notes:

  
o.

  
* 1 Acetic anhydride was used instead of acid

  
acetic and cobalt acetylacetonate was used
(bivalent) instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 181.1>

  
quantity of 10 mol% based on m-phenoxytoluene,

  
 <EMI ID = 182.1>

  
used aluminum bromide hexahydrate instead of sodium bromide.

  
* 3 Aluminum bromide was used as the brominated compound

  
and acetic anhydride was added in an amount

  
from 2 moles per mole of m-phenoxytoluene to the liquid of a standard composition in which the amount of acetic acid was 8 moles per mole of m-phenoxytoluene used.

  
* 4 One used prop ionic acid instead of acetic acid

  
and cobalt benzoate was used instead of cobalt acetate tetrahydrate.

  
* 5 Propionate.

  
 <EMI ID = 183.1>

  
this temperature in order to increase the rate of the reaction.

  
* 7 n-butyric acid was used instead of acetic acid

  
and cobalt stearate was used instead of cobalt acetate tetrahydrate.

  
 <EMI ID = 184.1>

  

 <EMI ID = 185.1>


  

 <EMI ID = 186.1>
 

  

 <EMI ID = 187.1>


  

 <EMI ID = 188.1>


  

 <EMI ID = 189.1>
 

  
Table 24
 <EMI ID = 190.1>
 
 <EMI ID = 191.1>
 <EMI ID = 192.1>
 <EMI ID = 193.1>
 
 <EMI ID = 194.1>
 <EMI ID = 195.1>
 
 <EMI ID = 196.1>
 <EMI ID = 197.1>
 
 <EMI ID = 198.1>
 <EMI ID = 199.1>
 Notes:

  
&#65533;

  
* 1 Presented as a molar ratio to

  
starting compound.

  
* 2 The rate or degree of selectivity with respect to

  
aldehyde, alcohol or acetate ester which has been formed by oxidation of only one methyl group or one of the methyl groups directly attached to the benzene ring.

  
* 3 The reaction did not occur below this

  
reaction temperature.

  
* 4 The reaction did not occur, although one had raised

  
slowly temperature up to 180 [deg.] C.

  
* 5 Paraldehyde was added in an amount of 2 mol%

  
based on the starting compound.

  

 <EMI ID = 200.1>


  

 <EMI ID = 201.1>


  

 <EMI ID = 202.1>
 

  

 <EMI ID = 203.1>


  

 <EMI ID = 204.1>


  

 <EMI ID = 205.1>
 

  
Table 28
 <EMI ID = 206.1>
 Notes:

  
\ t

  
* A commercially available reagent from

  
special grade (47-48% purity aqueous solution) as is.

  
* 2 Paraldehyde was not added.

  
 <EMI ID = 207.1>

  
per mole of the starting compound.

  
 <EMI ID = 208.1>

  
* 5 Acetaldehyde was added instead of paraldehyde.

  
* 6 No paraldehyde was added.

  
 <EMI ID = 209.1>
 <EMI ID = 210.1>
 Notes: -

  
In experiments marked with a white asterisk groin

  
 <EMI ID = 211.1>

  
acetic in an amount of 8 moles and acetic anhydride in an amount of 2 moles, per mole of the starting compound.

  
 <EMI ID = 212.1>

  
oxidizer instead of oxygen.

  
* 4 Cobalt acetylacetonate (bivalent) was used

  
as cobalt acetate tetrahydrate.

  
 <EMI ID = 213.1>

  
* 6 Cobalt stearate was used instead of acetate

  
cobalt tetrahydrate.

  
 <EMI ID = 214.1>

  
cobalt acetate tetrahydrate.

  
* 8 Cobalt benzoate was used instead of acetate

  
cobalt tetrahydrate.

  
* 9 Cobalt bromide was added in an amount of 0.1

  
mole per mole of the starting compound and sodium acetate in an amount of 0.2 mole per mole of the starting compound instead of using cobalt acetate tetrahydrate and sodium bromide.

  
 <EMI ID = 215.1>

  
of cobalt tetrahydrate.

  
* 11 With the exception of paraldehyde, the reaction mixture

  
liquid had the following composition:
3,4-diethoxytoluene: benzene: cobalt acetylacetonate
(bivalent): sodium bromide = 1: 4: 0.1: 0.01
 <EMI ID = 216.1>
 <EMI ID = 217.1>
 Notes:

  
* 1 Paraldehyde was not added.

  
* 2 These compounds were prepared by carrying out a process

  
customary using commercially available 2-methoxy-4-methylphenol as a starting material and carrying out its 0-ethylation with diethyl sulfate or its 0-butylation or its 0-octylation with the corresponding bromide and the compounds thus obtained were then purified before their use in the aforementioned manner.

  
* 3 Air (flow rate: 100 ml / min) was used as the agent

  
oxidant.

  
* 4 In the comparative examples, the bromide of

  
sodium and paraldehyde of the starting mixture according to the present invention.

  

 <EMI ID = 218.1>


  

 <EMI ID = 219.1>
 

  

 <EMI ID = 220.1>


  

 <EMI ID = 221.1>
 

  
Notes:

  
'&#65533;

  
* 1 Propionic acid was used instead of acid

  
acetic.

  
 <EMI ID = 222.1>

  
* 3 n-butyric acid was used instead of acid

  
acetic.

  
 <EMI ID = 223.1>

  
* 5 Acetic anhydride was used instead of acid

  
acetic.

  
* 6 A mixture of acetic acid and anhydride was used

  
acetic (4 moles: 1 mole in the mixture) instead of acetic acid.

  
* 7 Cobalt acetylacetonate (bivalent) was used

  
instead of cobalt acetate tetrahydrate.

  

 <EMI ID = 224.1>


  

 <EMI ID = 225.1>
 

  

 <EMI ID = 226.1>


  

 <EMI ID = 227.1>
 

  
 <EMI ID = 228.1>

  
Notes:

  
* 1 Expressed as a molar ratio to

  
starting compound.

  
* 2 Since the reaction rate was slow, the reaction temperature was gradually raised. In the case

  
 <EMI ID = 229.1>

  
 <EMI ID = 230.1>

  
sodium and paraldehyde of the starting mixture according to the present invention.

  

 <EMI ID = 231.1>


  

 <EMI ID = 232.1>


  

 <EMI ID = 233.1>
 

CLAIMS

  
1. Process for the production of alcohols and / or aldehydes, according to which a toluene derivative having one or more ether bonds of the following general formula is subjected:

  

 <EMI ID = 234.1>


  
in which RO represents an ether group where R represents

  
a hydrocarbyl group having 1 to 20 carbon atoms,

  
which may bear one or more inert substituents and n represents an integer equal to 1 or 2, as starting compound, to auto-oxidation, in liquid phase, with molecular oxygen, so as to generate l 'alcohol and / or the corresponding aldehyde, characterized in that the oxidation reaction is carried out using a lower saturated fatty acid and / or an anhydride of the latter as solvent, in the presence of a soluble cobalt salt and a substance providing bromine ions, to

  
a reaction temperature varying from 30 [deg.] C to 200 [deg.] C, in such a way that the degree of conversion of the starting compound does not exceed

  
 <EMI ID = 235.1>


    

Claims (1)

2. Method according to claim 1, characterized in that the the aforementioned cobalt salt is used in an amount of at least 0.001 mol per mole of the starting compound. 3. Method according to claim 1, characterized in that the amount of the substance providing bromine ions varies from 0.0001 to 0.5 mole per mole of starting compound, and concurrently from 0.001 to 10 moles per mole of the above-mentioned cobalt salt. 4. Method according to claim 1, characterized in that the lower saturated fatty acid is acetic acid and in this that its amount varies from 0.2 to 20 moles per mole of the starting compound. 5. Method according to claim 1, characterized in that the <EMI ID = 236.1> an ether group of a hydrocarbyl radical having 1 to 20 carbon atoms and in that the reaction is carried out under an oxygen partial pressure varying from 0.1 to 2 kg / cm2 (absolute pressure) at a temperature reaction which varies from 50 to 180 [deg.] C, in it presents cobalt salt in an amount of at least 0.01 mole per mole of the starting compound and of the substance providing A. <EMI ID = 237.1> bromine ions in an amount of 0.0001 to 0.5 mole per mole of the starting compound and concurrently 0.001 to 10 moles per mole of the aforementioned cobalt salt, such that the degree of conversion of said starting compound exceeds not 60%. 6. Method according to claim 5, characterized in that the lower saturated fatty acid is acetic acid and in that this acetic acid is used in an amount of 1 to 20 moles per mole of the starting compound. 7. The method of claim 5, characterized in that one uses, as solvent, a mixture of acetic acid in an amount of 2 to 15 moles per mole of the starting compound and acetic anhydride in an amount from 0.5 to 5 moles per mole of the starting compound. <EMI ID = 238.1> starting compound is m-phenoxytoluene or m-methoxytoluene and in that the reaction is carried out in the presence of the abovementioned cobalt salt in an amount of 0.005 to 0.3 mole per mole of the starting compound and in this that the aforementioned bromine ion-providing substance is used in an amount of 0.001 to 0.3 mole per mole of the starting compound and concurrently 0.005 to 5 moles per mole of the cobalt salt, at a reaction temperature varying from 60 [ deg.] C to 140 [deg.] C. 9. The method of claim 1, characterized in that the aforementioned starting compound is a toluene, the ortho position or the para position of which carries an ether group of a hydrocarbyl radical having 1 to 20 carbon atoms and in that the 'the reaction is carried out under a partial pressure of oxygen varying from 0.1 to 2 kg / cm2 (absolute pressure), at a reaction temperature which varies from 30 to 180 [deg.] C, in the presence of the aforementioned cobalt salt in an amount of at least 0.001 mole per mole of the starting compound in question and of said substance providing bromine ions in an amount of 0.0001 to 0.5 mole per mole of the above starting compound 10. The method of claim 9, characterized in that the lower saturated fatty acid is acetic acid and in that its amount varies from 0.2 to 20 moles per mole of the starting compound in question. 11. The method of claim 9, characterized in that one uses, as solvent, a mixture of acetic acid in an amount of 2 to 15 moles per mole of the starting compound and acetic anhydride in an amount. from 0.5 to 5 moles per mole of the compound <EMI ID = 239.1> <EMI ID = 240.1> stance providing bromine ions, in an amount of 0.0001 to 0.5 mole per mole of the starting compound and concurrently from 0.0002 to 20 moles per mole of the above-mentioned cobalt salt. 17. The method of claim 16, characterized in that the lower saturated fatty acid is acetic acid and in that its amount varies from 0.5 to 20 moles per mole of the starting compound in question. 18. The method of claim 16, characterized in that acetic acid is used as solvent and in that the reaction is carried out under a partial pressure of oxygen which varies. <EMI ID = 241.1> above, in an amount of 0.01 to 0.5 mole per mole of the compound starting point. 19. Process according to Claim 1, characterized in that the starting compound is a toluene having two ether groups of hydrocarbyl radicals having 1 to 20 carbon atoms and in that the reaction is carried out under partial pressure. oxygen which varies from 0.1 to 50 kg / cm2 (absolute pressure), at a temperature which varies from 40 to 200 [deg.] C, in the presence of the aforementioned cobalt salt in an amount of at least 0, 0005 mole per mole of the starting compound and the aforementioned bromine ion-providing substance in an amount of 0.00001 to 0.5 mole per mole of the starting compound and concurrently from 0.0002 to 20 moles per mole of the cobalt salt aforementioned, in such a way that the conversion rate of the compound of <EMI ID = 242.1> 20. The method of claim 19, characterized in that 3'one uses, as solvent, acetic acid in an amount of 0.5 to 20 moles per mole of the starting compound. 21. The method of claim 19, characterized in that the <EMI ID = 243.1> dimethoxytoluene and in that the reaction is carried out in the presence of the above-mentioned cobalt salt in an amount of at least 0.01 mole per mole of the starting compound in question, and of the substance providing bromine ions in an amount of 0.001 to 0.3 mole per mole <EMI ID = 244.1> toluene. 23. A process for the production of alcohol and / or aldehydes according to which a toluene derivative having one or more ether bonds corresponding to the following general structural formula is subjected: <EMI ID = 245.1> in which RO represents an ether group where R represents a hydrocarbyl radical having 1 to 20 carbon atoms, which may bear a substituent or inert substituents, and n represents an integer equal to 1 or 2, as a compound of starting with an auto-oxidation, in liquid phase, with molecular oxygen, so as to generate the corresponding alcohol and / or aldehyde, characterized in that the oxidation reaction in question is carried out in using, as solvent, a lower saturated fatty acid and / or an aldehyde thereof, in in an amount of 0.2 to 20 moles per mole of the above starting compound, in the presence of a soluble cobalt salt in an amount of at; <EMI ID = 246.1> providing bromine ions in an amount of 0.001 to 0.5 mole per mole of the starting compound and of a co-oxidant capable of generating <EMI ID = 247.1> quantity of 0.001 to 0.5 mole per mole of the abovementioned starting compound, in such a way that the degree of conversion of said starting compound does not exceed 90%. <EMI ID = 248.1> amount of the co-oxidant varies from 0.0001 to 0.5 mole per mole of the starting compound. 25. The method of claim 23, characterized in that the amount of said substance providing bromine ions varies from 0.0001 to 0.5 mole per mole of the starting compound, and concurrently from 0.001 to 10 mole per mole of the starting compound. cobalt salt. 26. A method according to claim 23, caraoterized in that <EMI ID = 249.1> <EMI ID = 250.1> mole of the aforementioned starting compound. 27. The method of claim 26, characterized in that the <EMI ID = 251.1> 28. Method according to claim 23, characterized in that the starting compound is a toluene, the meta position of which bears a <EMI ID = 252.1> carbon and in that said reaction is carried out under a partial pressure of oxygen which varies from 0.1 to 2 kg / cm2 (absolute pressure), at a reaction temperature which varies from 30 to 160 [deg.] C, in the presence of the aforementioned cobalt salt in an amount of at least 0.01 mole per mole of the starting compound, said substance providing bromine ions in an amount of 0.001 to 0.3 mole per mole of the starting compound and, concurrently 0.005 to 5 moles per mole of the above cobalt salt, and the above co-oxidant in an amount of 0.001 to 0.3 moles per mole of the above starting compound, such that the conversion rate of the above compound <EMI ID = 253.1> 29. The method of claim 28, characterized in that the lower saturated fatty acid and acetic acid and in that this acetic acid is used in an amount of 0.2 to 20 moles per mole of the aforementioned starting compound . 30. The method of claim 28, characterized in that the starting compound is m-phenoxytoluene or m-methoxytoluene and in that the reaction is carried out at a temperature which varies from 30 to 80 [deg.] C , in the presence of the above cobalt salt in an amount of 0.05 to 0.3 mole per mole of the starting compound, of the substance providing bromine ions in an amount of 0.001 to 0.3 mole per mole of the starting compound , and concurrently, from 0.005 to 5 moles per mole of the aforementioned cobalt salt, and said co-oxidant in an amount of 0.001 to 0.2 moles per mole of the aforementioned starting compound. 31, The method of claim 29p characterized in that the co-oxidant is chosen at least from the group formed by acetaldehyde, paraldehyde and methyl ethyl ketone. 32. The method of claim 23, characterized in that the aforementioned starting compound is a toluene, the ortho position or the para position of which bears an ether group of a hydrocarbyl radical having 1 to 20 carbon atoms and in that the 'the aforementioned reaction is carried out using, as solvent, the lower saturated fatty acid and / or an anhydride of the latter <EMI ID = 254.1> starting point, under a partial pressure of oxygen which varies from 0.1 to 2 kg / om2 (absolute pressure), at a reactive temperature <EMI ID = 255.1> above in an amount of 0.05 to 0.3 mole per mole of the starting compound, of said bromine ion-providing substance in an amount of 0.001 to 0.3 mole per mole of said starting compound and, concurrently, of 0.005 to 5 moles per mole of said cobalt salt and said co-oxidant in an amount of 0.001 to 0.2 moles per mole of the above starting compound. 33. The method of claim 32, characterized in that the lower saturated fatty acid is acetic acid and in that this acetic acid is used in an amount of 2 to 5 moles per mole of the aforementioned starting compound. 34. The method of claim 23, characterized in that the starting compound is a toluene whose meta position bears an ether group of a hydrocarbyl radical having 1 to 20 atoms. of carbon and in that the reaction is carried out under a partial pressure of oxygen which varies from 2 to 50 kg / cm2 (absolute pressure), at a reaction temperature which varies from 40 to 180 [deg.] C, in the presence of the above-mentioned cobalt salt in an amount of at least 0.01 mole per mole of said starting compound, said substance providing bromine ions in an amount of 0.001 to 0.3% per mole of said starting compound and, concurrently, 0.001 to 10 moles per mole of said cobalt salt and co- aforementioned oxidant in an amount <EMI ID = 256.1> such that the degree of conversion of said starting compound does not exceed 60%. 35. The method of claim 34, characterized in that the lower saturated fatty acid is acetic acid and in that this acetic acid is used in an amount of 5 to 15 moles per mole of said starting compound. 36. The method of claim 34, characterized in that acetic acid is used as solvent and in that the reaction is carried out under a partial pressure of oxygen which varies from 3 to 50 kg / cm2 (absolute pressure), in the presence of the above-mentioned cobalt salt in an amount of 0.001 to 0.5 mol per mol of the above-mentioned starting compound. 37. The method of claim 34, characterized in that the aforementioned starting compound and m-phenoxytpluene or m-methoxytoluene and in that the reaction is carried out using, as solvent, acetic acid in an amount of 5 to 15 moles per mole of the abovementioned starting compound, under a partial pressure of oxygen which varies from 10 to 50 kg / cm2 (absolute pressure); at a reaction temperature which varies from 50 to 150 [deg.] C, in the presence of the above-mentioned cobalt salt in an amount of 0.01 to 0.5 mol per mol of the above-mentioned starting compound, of said substance providing bromine ions in an amount of 0.001 to 0.3 mole per mole of the above starting compound and, concurrently, 0.01 to 10 moles per mole of the above cobalt salt, and the above co-oxidant in one <EMI ID = 257.1> 38. The method of claim 23, characterized in that the starting compound is a toluene, the ortho position or the para position of which carries an ether group of a hydrocarbyl radical having 1 to 20 carbon atoms and in that the said reaction is carried out under a partial pressure of oxygen which varies from 2 to 50 kg / cm2 (absolute pressure), at a reaction temperature which varies from 40 to 180 [deg.] C, in the presence of the above-mentioned cobalt salt in an amount of at least 0.01 mole per mole of the starting compound, of said substance supplying bromine ions in an amount of 0.001 to 0.3 mole per mole of the above starting compound and, concurrently, 0.001 to 10 moles per mole of the above cobalt salt and which co-oxidizes above in an amount 0.005 to 0.1 mole per mole of the above starting compound. 39. The method of claim 38, characterized in that the aforementioned saturated fatty acid is acetic acid and in that one <EMI ID = 258.1> mole of the aforementioned starting compound. 40. The method of claim 38, characterized in that the aforementioned reaction is carried out using acetic acid as the aforementioned solvent, under a partial pressure of oxygen which varies from 3 to 50 kg / cm2 (absolute pressure), in presence of the above-mentioned cobalt salt in an amount of 0.01 to 0.5 mole per mole of the above-mentioned starting compound. 41. Process according to claim 23, characterized in that the aforementioned starting compound is a toluene which carries two ether groups of hydrocarbyl radicals having from 1 to 20 carbon atoms and in that the aforementioned reaction is carried out under pressure partial oxygen which varies from 0.1 to 50 kg / cm2 (absolute pressure), at a reaction temperature which varies from <EMI ID = 259.1> <EMI ID = 260.1> 1 42. The method of claim 41, characterized in that one uses, as solvent, acetic acid in an amount from 0.5 to 20 moles per mole of said starting compound. 43. The method of claim 43, characterized in that the <EMI ID = 261.1> dimethoxytoluene and in that the reaction is carried out in the presence of the cobalt salt in an amount of at least 0.01 mole per mole of the aforementioned starting compound, of said substance providing bromine ions in an amount of 0.001 to 0 , 3 mole per mole of the above starting compound and, concurrently, 0.001 to 10 moles per mole of the above cobalt salt and the above co-oxidant in an amount of 0.001 to 0.5 mole per mole of the above starting compound. 44. The method of claim 43, characterized in that the starting compound is 3,4-diethoxytoluene or 2,3-diethoxytoluene and in that the aforementioned co-oxidant is chosen at least from the group formed by the acetaldehyde, paraldehyde and methyl ethyl ketone.