Improvements in the Preparation of Paramidophenol and the like.
Year: 1897

page_text: .
Improvements in the Preparation of Paramidophenol and the like.
I, HENRI RAYMOND VIDAL, of 95, Boulevard Beaumarchais, Paris, in the Republic
of France, Chemical Engineer, do hereby declare the nature of this invention to be
as follows
- :i
The reduction of oxy-azo-benzol or of paranitrophenol by sulphide of sodium alone
causes the production of equal parts of ill defined products and of paramidophenol.
I have found that if a certain quantity of a caustic alkali, such as caustic soda, is
added, the foreign products are not occasioned and paramidophenol is exclusively
obtained.
With this object I heat in an iron cauldron, which is provided with an agitator:
Sulphide of sodium
Oxy-azo-benzol
Caustic Soda
-
-
3 kilos.
-
2
"7
100 grammes
1
kilo.
:)
I raise the mass to a temperature of 180° C., and I repeat by the addition of water
until the yellow colouration of the oxy-azo-benzol has disappeared.
I then allow the, mass to, dry and remove it from the apparatus.
The mass
dissolved in water is precipitated by an acid and the paramidophenol is collected upon-
a filter.
I reserve to myself the right of reducing under the same conditions, ortho-nitro-
phenol, the di-nitrophenols 1-2-4 and 1-2-6 and the like, in order to obtain the
corresponding amido compounds.
Dated this 3rd day of March 1897.
5 Improvements in the Preparation of Paramidophenol and the like.
I, HENRY RAYMOND VIDAL, of 95, Boulevard Beaumarchais, Paris, in the Republic of
France, Chemical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
The reduction of oxy-azo-benzol or of paranitrophenol by sulphide of sodium
alone causes the production of equal parts of ill defined products and of paramido-
phenol

page_text: I have found that it a certam quantity of a caustic alkali, such
added, the foreign products are not occasioned and paramidophenol is exclusively
obtained.
With this object I heat in an iron cauldron, which is provided with an agitator:
Sulphide of sodium
Oxy-azo-benzol
Caustic Soda
-
=
3 kilos.
2
"
-
1
"
-
100 grammes
I raise the mass to a temperature of 180° C., and I repeat by the addition of water
until the yellow colouration of the oxy-azo-benzol has disappeared.
I then allow the mass to dry and remove it from the apparatus. The mass dissolved
in water is precipitated by an acid and the paramidophenol is collected upon a filter.
I reserve to myself the right of reducing under the same conditions, ortho-
nitrophenol, the di-nitrophenols 1-2-4 and 1-2-6 and the like, in order to obtain the
corresponding amido compounds.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A method of manufacturing paramidophenol consisting in heating, with sulphide
of sodium; oxyazobenzole or paranitrophenol or a mixture of these two substances, in
the presence of caustic soda.
2. A method of manufacturing paramidophenol, consisting in heating, with sulphide
of sodium, oxyazobenzole or paranitrophenol or a mixture of these two substances, in
the presence of caustic soda, care being taken that from time to time water be added
to the mass raised to a temperature of about 180 degrees, until the complete
disappearance of the yellow colour given by either oxyazobenzole or paranitrophenol.
3. The method of treating the product resulting from the action of the sulphide
of sodium, in the presence of caustic soda upon oxyazobenzole or paranitrophenol
or a mixture of these two substances, consisting in desiccating the product in
dissolving the same in water, in precipitating the paramidophenol by neutralizing
the solution by means of an acid, and in collecting the paramidophenol precipitated
upon a filter.
4. In the methods ascertained in the first and second claims the substitution
for oxyazobenzole and paranitrophenol, of orthonitrophenol and of dinitrophenols 1-2-4
and 1-2-6 with the view to obtaining the corresponding amidated compounds under
the same conditions.
Dated this 3rd day of December 1837.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.