Process for the preparation of N-acylated p-amino-phenols

N-acylated p-amino-phenols can be prepared by catalytical hydrogenation of the underlying aromatic nitro compounds in a reaction medium of aqueous sulfuric acid in the sense of a Bamberger type reaction at elevated temperature, optionally in the presence of a water-miscible organic solvent, and subsequent reaction of this reaction mixture with an acid chloride, optionally in the presence of an acid binder and optionally in the presence of a diluent.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a process for the preparation of N-acylated 
p-amino phenols by catalytic hydrogenation or aromatic nitro compound 
having a free p position in accordance with a Bamberger reaction and 
subsequent acylation of the resulting amino group. 
N-acylated p-amino-phenols are known as pest control agents, in particular 
as fungicides (EP 339 418). 
2. Description of the Related Art 
The preparation of N-acylated p-amino-phenols is conventionally carried out 
by acylation of the corresponding free p-amino-phenols in the presence of 
diluents and with the aid of basic auxiliaries (EP 339 418). The 
p-amino-phenols required are compounds known in principle and are 
generally prepared by nitration of p-unsubstituted hyroxyaromatic 
compounds and subsequent reduction of the nitro group or by reduction of 
p-unsubstituted nitro-aromatic compounds in accordance with a Bamberger 
reaction (Houben-Weyl, 4th edition, Volume VI/1c; (1976), pp. 85-117). In 
both cases it is conventional and necessary to isolated the free 
p-amino-phenols required as intermediates for the preparation of the 
desired N-acylated p-amino-phenols and to react them further in purified 
form. This procedure is complex, uneconomic and associated with losses in 
yield and high production of wastes, in particular effluents. Moreover, 
the nitration of phenols gives cause for concern with respect to reaction 
and safety aspects. 
SUMMARY OF THE INVENTION 
The object was therefore to find a process for the preparation of the 
abovementioned N-acylated p-amino-phenols which avoids multi-step and 
complicated reaction sequences, avoids the nitration of hydroxyaromatic 
compounds and which leads to products of high purity in good yields. 
This object is achieved by the process according to the invention without 
intermediate isolation of the p-amino-phenol. 
The present invention relates to a process for the preparation of 
N-acylated p-amino-phenols of the general formula 
##STR1## 
in which A represents a benzene or naphthalene nucleus, 
p indicates the p position to the amino group, 
R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently of each other, denote 
hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, halogen or 
the group CO--R.sup.6 in which R.sup.6 represents hydrogen, C.sub.1 
-C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, hydroxyl or unsubstituted or 
substituted aryl, and 
R.sup.5 denotes C.sub.1 -C.sub.20 -alkyl, C.sub.3 -C.sub.10 -cycloalkyl, 
C.sub.5 -C.sub.10 -cycloalkenyl, C.sub.1 -C.sub.10 -alkoxy, unsubstituted 
or substituted aryloxy or unsubstituted or substituted aryl, 
which is characterised in that nitro compounds of the general formula 
##STR2## 
in which R.sup.1 to R.sup.4, A and p have the above meanings, are 
hydrogenated in an aqueous acidic reaction medium in which the amount of 
water is 2 to 40 times, preferably 3 to 30 times, particularly preferably 
4 to 20 times, the amount by weight of the aromatic nitro compound, and in 
the absence or presence of a water-miscible organic solvent with the aid 
of a catalyst selected from the group comprising the platinum metals in 
accordance with a Bamberger reaction at a temperature of 
50.degree.-160.degree. C., preferably 70.degree.-140.degree. C., 
particularly preferably 90.degree.-120.degree. C. and a hydrogen partial 
pressure of 0.1-50 bar, preferably 0.5-30 bar, particularly preferably 
1-20 bar and the resulting reaction mixture is reacted with a compound of 
the formula 
##STR3## 
where R.sup.5 has the above iteanina and 
X represents a leaving group, 
in an amount of 0.5-2 mol, preferably 0.8-1.4 mol, per mol of the nitro 
compound used, at a temperature of -30.degree. C. to +150.degree. C., 
preferably -20.degree. C. to +120.degree. C., particularly preferably 
-10.degree. C. to +100.degree. C., and in the absence or presence of a 
basic auxiliary or another acid acceptor and in the absence or presence of 
a diluent. 
DETAILED DESCRIPTION OF THE INVENTION 
It is a surprising advantage of the process according to the invention that 
the reaction mixture obtained in the catalytic hydrogenation of 
p-unsubstituted nitroaromatic compounds under aqueous acidic conditions in 
accordance with a Bamberger reaction can he reacted smoothly with 
acylation agents of the general formula (III), the desired products of the 
general formula (I) being obtained without the losses in yields, caused by 
hydrolysis of the abovementioned acylation agents of the formula (III), 
being observed. 
A further surprising advantage of the process according to the invention is 
that the desired products of the general formula (I) are obtained in high 
purities although isolation and intermediate purification of the 
p-amino-phenols occurring as intermediates, as in the prior art, is 
dispensed with. 
Further advantages are: 
the reduction of effluent pollution compared with the previous process 
the increase of the economic efficiency by reduction of the number of the 
required process steps. 
C.sub.1 -C.sub.4 -alkyl is, for example, methyl, ethyl, propyl, 2-propyl, 
butyl, 2-butyl, 2-methyl-propyl (isobutyl), 2-methyl-2-propyl 
(tert-butyl); a further alkyl having up to 20 C atoms is, for example, 
pentyl, 2-pentyl, 3-pentyl, 2,2-dimethyl-propyl (neopentyl), 
2-methyl-2-butyl, 3-methyl-2-butyl, hexyl, 2-hexyl, 3-methyl-3-pentyl, 
3,3-dimethyl-2-butyl, 2,2-dimethyl-butyl, heptyl, octyl, nonyl, decyl, 
pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl. The 
substituents R.sup.1, R.sup.2,R.sup.3, R.sup.4 and R.sup.5 preferably 
denote, independently of each other, methyl and ethyl, particularly 
preferably methyl. The substituent R.sup.5 preferably denotes 
straight-chain or branched alkyl having up to 8 carbon atoms of the 
above-mentioned type, particularly preferably branched alkyl having up to 
6 carbon atoms of the abovementioned type. 
C.sub.1 -C.sub.4 -alkoxy is straight-chain or branched alkyl of the 
abovementioned type linked via an oxygen atom; correspondingly, alkoxy is 
taken to mean having up to 10 C atoms. The substituents R.sup.1, R.sup.2, 
R.sup.3, R.sup.4 and R.sup.6 preferably denote, independently of each 
other, C.sub.1 -C.sub.2 -alkoxy, particularly preferably methoxy. The 
substituent R.sup.5 preferably denotes straight-chain or branched alkoxy 
having up to 8 carbon atoms, particularly preferably straight-chain or 
branched alkoxy having up to 6 carbon atoms. 
C.sub.3 -C.sub.10 -cycloalkyl denotes saturated, unsubstituted or 
substituted, preferably 3- to 8-membered, particularly preferably 3- to 
6-membered, carbocyclic ring systems, where substituents which may be 
mentioned are, for example, halogen, preferably fluorine or chlorine, and 
lower alkyl having 1 to 4 carbon atoms, preferably methyl. In this 
context, cyclopropyl, 1-methyl-cyclopropyl, 1-fluoro-cyclopropyl, 
1-chloro-cyclopropyl, cyclobutyl, 1-methyl-cyclobutyl, 
heptafluoro-cyclobutyl, cyclopentyl, 1-methyl-cyclopentyl, 
2,2-dimethyl-cyclopentyl, cyclohexyl, 1-methyl-cyclohexyl, 
4,4-dimethylcyclohexyl, 4-tert-butyl-cyclohexyl and 1-adamantyl may be 
mentioned in particular. 
C.sub.5 -C.sub.10 -cycloalkenyl denotes monounsaturated or polyunsaturated, 
non-aromatic, unsubstituted or substituted, preferably 5- to 8-membered, 
particularly preferably 5- and 6-membered, carbocyclic ring systems, where 
substituents which may be mentioned are, for example, halogen, preferably 
fluorine or chlorine, and lower alkyl having 1 to 4 carbon atoms, 
preferably methyl. 1-, 2- and 3-cyclopentenyl, 1-, 2-, 3- and 
4-cyclohexenyl, 2-methyl-2-cyclopentenyl, 3-methyl-3-cyclopentenyl, 
2-methyl-2-cyclohexenyl, 2-chloro-2-cyclohexenyl, 1-methyl-4-cyclohexenyl 
and 1,5-dimethyl-5-cyclohexenyl may be mentioned in particular. 
Aryl denotes unsubstituted or substituted phenyl having up to 5, preferably 
up to 4, particularly preferably up to 3, substituents, which can take up 
any positions in ortho- meta- or para-position to each other. Preferred 
substituents are halogen, in particular fluorine or chlorine, C.sub.1 
-C.sub.4 -alkyl, preferably methyl, halogenoalkyl, preferably 
trifluoromethyl and difluoromethyl, C.sub.1 -C.sub.4 -alkoxy, preferably 
methoxy and ethoxy, halogenoalkyloxy, preferably trifluoromethoxy and 
tetrafluoroethoxy and C.sub.1 -C.sub.4 -alkoxycarbonyl, preferably 
methoxycarbonyl and ethoxycarbonyl. 
Aryloxy denotes unsubstituted or substituted phenyl, linked via an oxygen 
atom, having up to 5, preferably up to 4, particularly preferably up to 3, 
substituents which can take up any positions in ortho-, meta- or 
paraposition to each other. Preferred substituents are halogen, in 
particular fluorine or chlorine, C.sub.1 -C.sub.4 -alkyl, preferably 
methyl, halogenoalkyl, preferably trifluoromethyl and difluoromethyl, 
C.sub.1 -C.sub.4 -alkoxy, preferably methoxy and ethoxy, halogenoalkyloxy, 
preferably trifluoromethoxy and tetrafluoroethoxy and alkoxycarbonyl, 
preferably methoxycarbonyl and ethoxycarbonyl. Halogen denotes, for 
example, fluorine, chlorine or bromine, preferably fluorine or chlorine. 
The leaving group X represents, for example, halogen, preferably fluorine, 
chlorine or bromine, particularly preferably chlorine, the radical 
O-R.sup.5 or the radical O-CO-R.sup.5, in which R.sup.5 has the 
abovementioned meaning. Moreover, in principle, all leaving groups X are 
suitable which ensure a sufficient activation of the radical CO-R.sup.5 in 
accordance with an acylation, for example alkoxy. Carrying out the process 
according to the invention may be described with reference to the 
following example: 
##STR4## 
Suitable cosolvents which may optionally be used in accordance with the 
present invention are in principle all organic, water-miscible solvents 
which are stable under the reaction conditions used and which do not 
negatively influence the catalytic hydrogenation. Such cosolvents are, for 
example, lower alcohols and polyhydric alcohols having 1 to 4 C atoms, 
such as methanol, ethanol, n- and i-propanol, n-, i-, sec- and 
tert-butanol, ethylene glycol, 1,2- and 1,3-propanediol, 1,2-, 1,3-, 1,4- 
and 2,4-butanediol and 1,2,3-propanetriol. Further examples are 
water-soluble ethers of the polyhydric alcohols mentioned such as glycol 
monomethyl ether and glycol dimethyl ether, glycol monoethyl ether and 
glycol diethyl ether. Examples of further cosolvents which may be used 
according to the invention are water-soluble cyclic ethers, such as 
tetrahydrofuran and dioxan, water-miscible ketones, such as acetone and 
methyl ethyl ketone, water-soluble carboxylic amides, in particular those 
alkylated twice on the nitrogen atom, such as N,N-dimethylacetamide, 
N,N-dimethylformamide and the corresponding ethylated lower carboxylic 
amides, and lower aliphatic carboxylic acids having 1 to 4 C atoms, such 
as formic acid, acetic acid or propionic acid. The abovementioned lower 
alcohols ethylene glycol and its monomethyl and dimethyl ethers of the 
abovementioned type and dioxan may be preferably mentioned. Methanol, 
ethanol, ethylene glycol, glycol monomethyl ether and glycol dimethyl 
ether and dioxan may be particularly preferably mentioned. The 
abovementioned cosolvents can be used either individually or alternatively 
as a mixture of a plurality thereof. 
The amount of the organic, water-miscible solvent which may be used is 0.01 
to 3 times, preferably 0.03 to 2 times, particularly preferably 0. 05 to 1 
times the amount by weight of the aromatic nitro compound. 
Strong inorganic or organic acids are useful for the aqueous acidic 
reaction medium, for example, sulphuric acid, phosphoric acid, nitric 
acid, hydrochloric acid, perchloric acid, methanesulphonic acid, 
toluenesulphonic acid, perfluoromethanesulphonic acid and others known to 
those skilled in the art. Sulphuric acid or one of the sulphonic acids 
mentioned are preferably used; sulphuric acid is particularly preferably 
used. 
The amount of the strong acids is 0.4 to 10 equivalents, preferably 0.5 to 
2 equivalents, particularly preferably 0.5 to 1.2 equivalents, based on 1 
mol of the aromatic nitro compound. 
The amount of water for the aqueous acidic reaction medium is 2 to 40 
times, preferably 3 to 30 times, particularly preferably 4 to 20 times the 
amount by weight of the aromatic nitro compound. 
The process according to the invention is carried out at a temperature of 
50.degree. to 160.degree. C., preferably 60.degree. to 140.degree. C,. 
particularly preferably 70.degree. to 120.degree. C. 
Elevated pressure is employed for the catalytic hydrogenation in the 
context of the process according to the invention, for which purpose a 
pressure reactor of any desired type, such as is known to those skilled in 
the art, is employed. Obviously, such a reactor is acid-resistant under 
the reaction conditions to be established according to the invention. A 
pressure of 2 bar up to 50 bar may be mentioned as elevated pressure. At 
this elevated pressure, the hydrogen partial vapour pressure accounts for 
0.1 to 50 bar, preferably 0.5 to 30 bar, particularly preferably 1 to 20 
bar, and therefore can thus also go to make up the overall pressure of up 
to 50 bar. The difference between the hydrogen partial vapour pressure and 
the overall pressure is generally the inherent pressure of the reaction 
system, that is the vapour pressure of the water and of the organic, 
water-miscible solvent to be added. The vapour pressure of the nitro 
compound additionally contributes. Furthermore, after filling the pressure 
reactor with the substances to be reacted and the reaction medium, 
flushing with inert gas, such as nitrogen, noble gas etc., is necessary 
for the problem-free course of a catalytic hydrogenation. A residue of the 
inert flushing gas remaining in the pressure reactor after it has been 
closed also contributes to the overall pressure. A procedure is generally 
followed for this such that the closed pressure reactor is brought to the 
desired reaction temperature before the hydrogen partial vapour pressure 
is established by forcing in hydrogen. Hydrogen is then added for as long 
as it is taken up by the reaction mixture. 
Catalysts which are useful for the process according to the invention are 
noble metals selected from the platinum group, in particular platinum 
and/or palladium. Similarly, compounds of the platinum metals, for example 
platinum compounds and/or palladium compounds, can be used. These 
compounds are then reduced by the hydrogenating hydrogen to form platinum 
metal active in hydrogenation. The platinum metal or a compound of the 
platinum metal can be used with or without a support. Supports can, for 
example, be silica gel, aluminum oxide, zeolites, molecular sieves, 
charcoal or other supports known to those skilled in the art, preferably 
charcoal. When a support is used with the catalyst, the metal coating is 
0.05 to 8% by weight, preferably 0.1 to 6% by weight, particularly 
preferably 0.25 to 5% by weight of the total catalyst. The catalyst, with 
or without support, is used in such an amount that 0.001 to 0.3% by 
weight, preferably 0.005 to 0.1% by weight, particularly preferably 0.01 
to 0.1% by weight of the platinum metal is present, based on the nitro 
compound to be reacted. 
The entire reaction mixture is intensively stirred during the hydrogen 
uptake. For this purpose the pressure reactor is equipped with an agitator 
or a lifting device or is designed as a shaking autoclave. 
It is characteristic of the process according to the invention that the 
catalysts used, after termination of the reduction step or after 
termination of the entire reaction sequence, preferably after termination 
of the reduction step, can be recovered in an unchanged active or almost 
unchanged active form. 
The isolation of the catalyst after termination of the reduction step or 
after the entire reaction sequence is achieved by filtration, decanting or 
centrifugation from the remaining reaction mixture. 
If the removal and recovery of the catalyst is carried out immediately 
after the reduction step, it can, possibly, be advantageous to wholly or 
partly remove from the reaction mixture any cosolvent possibly used in the 
course of carrying out this reduction step. This can be carried out at 
elevated or reduced pressure or at atmospheric pressure by distillation, 
preferably by distillation at reduced pressure. 
Diluents which are useful for carrying out the 2nd reaction step of the 
process according to the invention are organic solvents which are inert 
under the reaction conditions. These include, in particular, aliphatic, 
alicyclic or aromatic, unhalogenated or halogenated hydrocarbons such as 
benzine, benzene, toluene, xylene, chlorobenzene, petroleum ether, hexane, 
cyclohexane, dichloromethane, chloroform, carbon tetrachloride, ethers 
such as diethyl ether, dioxan, tetrahydrofuran or ethylene glycol dimethyl 
ether or ethylene glycol diethyl ether, ketones such as acetone or 
butanone, nitriles such as acetonitrile or propionitrile, amides such as 
dimethylformamide, dimethylacetamide, N-methylformanilide, 
N-methylpyrrolidone or hexamethylphosphoric triamide, esters such as ethyl 
acetate or sulphoxides such as dimethyl sulphoxide. 
The 2nd reaction step of the process according to the reaction can thus be 
carried out in a two-phase system, such as water/toluene or 
water/dichloromethane, in the absence or presence of a phase transfer 
catalyst. Examples of such catalysts which may be mentioned are: 
tetrabutylammonium iodide, tetrabutylammonium bromide, 
tributyl-methylphosphonium bromide, trimethyl-C.sub.13 /C.sub.15 
-alkylammonium chloride, dibenzyldimethyl-ammonium ethyl sulphate, 
dimethyl-C.sub.12 /C.sub.14 -alkylbenzylammonium chloride, 
tetrabutylammonium hydroxide, 15-crown-5, 18-crown-6, 
triethylbenzylammonium chloride, trimethylbenzylammonium chloride or 
tris-[2-(2-methoxy-ethoxy)-ethyl]-amine. 
Basic auxiliaries which are useful for carrying out the 2nd reaction step 
of the process according to the invention are all conventionally usable 
inorganic and organic bases. Alkali metal hydroxides or alkaline earth 
metal hydroxides, alkali metal carbonates or hydrogen carbonates or 
alkaline earth metal carbonates or hydrogen carbonates, such as potassium 
hydroxide, calcium hydroxide, sodium hydroxide, potassium carbonate, 
calcium carbonate, sodium carbonate or sodium hydrogen carbonate or 
tertiary amines such as triethylamine, N,N-dimethylaniline, pyridine, 
N,N-dimethylaminopyridine, diazabicyclooctane (DABCO) , diazabicyclononene 
(DBN) or diazabicycloundecene (DBU) are preferably used. 
The reaction temperatures can be varied within a relatively wide range when 
the 2nd reaction step of the process according to the invention is carried 
out. Generally, temperatures between -30.degree. C. and +150.degree. C. 
are employed, preferably temperatures between -20.degree. C. and 
120.degree. C., particularly preferably temperatures from -10.degree. C. 
to +100.degree. C. 
The 2nd part-step of the process according to the invention is generally 
carried out at atmospheric pressure. However, it is also possible to carry 
it out at reduced or elevated pressure. 
To carry out the 2nd part-step of the novel process according to the 
invention, 0.5 to 2.0 mol of the acylation reagent (for example the acid 
chloride), preferably 0.8 to 1.4 mol, and 2 to 5 mol of the basic 
auxiliary (for example sodium hydroxide), preferably 3 to 4 mol per mol of 
the nitroaromatic compound used as starting material are generally used. 
The reaction procedure, work-up and isolation of the reaction products are 
carried out by generally conventional methods (see also the preparation 
examples). 
The process according to the invention is carried out using a nitrobenzene 
or a 1-nitro-naphthalene which can be substituted in accordance with 
formula (II). It is preferably carried out using a nitrobenzene which can 
be substituted in accordance with formula (II). 
Important aromatic nitro compounds as starting materials for the process 
according to the invention are: nitrobenzene, 2-nitrotoluene, 
3-nitrotoluene, 2-chloronitrobenzene, 3-chloro-nitrobenzene, 
2-ethyl-nitrobenzene, 3-ethyl-nitrobenzene, 2-acetyl-nitrobenzene, 
3-acetyl-nitrobenzene, 2-nitrobenzoic acid and esters, 3-nitrobenzoic acid 
and esters, 2-fluoro-nitrobenzene, 3-fluoro-nitrobenzene, 
2,3-dichloro-nitrobenzene, 2,3-difluoro-nitrobenzene, 
2-chloro-3-fluoro-nitrobenzene, 2-fluoro-3-chloro-nitrobenzene, 
1-nitronaphthalene, 2-chloro-3-methyl-nitrobenzene, 
2-methyl-3-chloro-nitrobenzene. 
From such nitro compounds, according to the invention, are formed the 
corresponding p-aminophenols, preferably those of the benzene series, 
which are then acylated according to the invention. 
The following aromatic nitro compounds of the benzene series may preferably 
be mentioned from which are formed the corresponding p-aminophenols of the 
benzene series which are then to be acylated: 2,3-dichloro-nitrobenzene, 
3-nitrobenzoic acid, 2-fluoro-nitrobenzene, 3-fluoro-nitrobenzene, 
2-nitrotoluene, 3-nitrotoluene, 2-chloro-nitrobenzene, 
3-chloro-nitrobenzene, 2-nitrobenzoic acid, 
2-chloro-3-fluoro-nitrobenzene, 2-fluoro-3-chloro-nitro-benzene, 
2-chloro-3-methyl-nitrobenzene and 2-methyl-3-chloro-nitrobenzene.

EXAMPLE 1 
96 g (0.5 mol) of 2,3-dichloronitrobenzene, 20 ml of dimethoxyethane (DME), 
400 ml of water, 60 g of 98% strength (0.6 mol) sulphuric acid and 1 g of 
platinum catalyst (5% on activated charcoal) were introduced into a 1.3 l 
enamel autoclave and heated with vigorous stirring to 105.degree. C. 
10 bar of hydrogen were then applied and the mixture was hydrogenated to 
constant pressure. 
200 ml of water were added to the reaction mixture and this was filtered 
hot. 
150 ml of DME/water mixture were distilled off on a rotary evaporator and 
the resulting suspension was transferred into a four-necked flask equipped 
with stirrer, reflux condenser, dropping funnel and pH electrode. 
The mixture was adjusted to pH 5.5 using 20% strength sodium hydroxide 
solution, 250 ml of toluene were added and the mixture was heated to 
50.degree. C. 
30.5 g (0.19 mol) of 1-methylcyclohexanecarbonyl chloride were added 
dropwise in the course of 30 min, the mixture was stirred for a further 10 
min and then adjusted to pH 4.5 using 20% sodium hydroxide solution. 
14.5 g (0.09 mol) of acyl chloride were then added dropwise four times 
successively in the course of 15 min, the mixture was stirred for a 
further 5 min and the pH was adjusted to 5.5 using 20% strength sodium 
hydroxide solution. 
After the last addition of sodium hydroxide solution, the mixture was 
stirred for a further 1 hour, adjusted to pH 2.5 using concentrated HCl, 
heated to 80.degree. C., adjusted to pH 1.5 using concentrated HCl and 
stirred for a further 1 hour. 
The mixture was cooled to 0.degree. C. in the course of 2 hours, filtered 
using suction and washed at room temperature using 2.times.100 ml of 
water. 
After drying, 2',3'-dichloro-4'-hydroxy-1'-methylcyclohexanecarboxanilide 
was obtained in 70% yield (based on 2,3-dichloronitrobenzene used). 
EXAMPLE 2 
The reaction sequence of Example 1 was repeated, 22.9 g and 4.times.10.9 g 
of pivaloyl chloride being used instead of 1-methylcyclohexanecarbonyl 
chloride. 2',3'-dichloro-4'-hydroxypivalanilide was obtained in 72% yield 
(based on 2,3-dichloronitrobenzene used). 
EXAMPLE 3 
42.9 g (0.276 mol) of 2-chloro-3-nitrotoluene, 80 ml of dimethoxyethane, 
400 ml of H.sub.2 O, 30 g of H.sub.2 SO.sub.4 (98% strength=0.3 mol) and 2 
g of 5% Pt/C were placed in a 1.3 l enamel autoclave and heated with 
vigorous stirring to 100.degree. C. 
10 bar of hydrogen were then applied and the mixture was hydrogenated to 
constant pressure. 
The reaction mixture was filtered hot, concentrated on a rotary evaporator 
to 300 ml and transferred into a four-necked flask equipped with stirrer, 
reflux condenser, dropping funnel and pH electrode. 
The mixture was adjusted to pH 5.5 using 20% strength sodium hydroxide 
solution, 100 ml of toluene were added and the mixture was heated to 
50.degree. C. 
15.8 g (0.1 mol) of 1-methylcyclohexanecarbonyl chloride were added 
dropwise in the course of 20 min, the mixture was stirred for a further 5 
min and again adjusted to pH 5.5 using 20% strength sodium hydroxide 
solution. 
7.2 g (0.045 mol) of carbonyl chloride were then added dropwise in each of 
four steps in the course of 10 min, the mixture was stirred for a further 
3 min and adjusted to pH 5.5 using 20% strength sodium hydroxide solution. 
After the last addition of sodium hydroxide solution, the mixture was 
stirred for a further 30 min, adjusted to pH 2.5 using concentrated HCl, 
heated to 80.degree. C., adjusted to pH 1.5 using concentrated HCl and 
stirred for a further 30 min. 
The mixture was cooled to 0.degree. C. in the course of 2 hours, filtered 
using suction and washed at room temperature using 3.times.50 ml of water. 
After drying, 77% 
2'-chloro-4'-hydroxy-1,3'-dimethylcyclohexanecarboxanilide were obtained.