Manufacture of m-oxybenzaldehyde-o-sulphonic Acid.
Year: 1897

page_text: Manufacture of m-oxybenzaldehyde-o-sulphonic Acid.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, Chancery'
Lane, in the County of London, Chartered Patent Agent, do hereby declare the
nature of this invention (as communicated to me from abroad by The Farbwerke
vormals Meister Lucius and Bruning, of Hoechst a/Main, in the Empire of
Germany, Chemical Manufacturers), to be as follows:-
A sulphonic acid of m-oxybenzaldehyde has hitherto been unknown.
Meta-oxybenzaldehyde cannot be sulphonated in the usual way, for, if it is
treated with sulphuric acid it undergoes complete decomposition with separation
of carbon.
T
My correspondents have found that m-oxybenzaldehyde-ortho-sulphonic acid.
(COH: OH: SO₂OH=1:3:6), of great value in the manufacture of acid dyestuffs,
of the series of "malachite green," may easily be obtained from m-amidobenzalde-
hyde-ortho-sulphonic acid.
The process may for instance be carried out as follows:-
20.1 kilos. of m-amidobenzaldehyde-o-sulphonic acid or the equivalent quantity
of one of its salts are dissolved in about 500 litres of water to which are added
40 kilos. of sulphuric acid of 66° Be. and cooled down to 0° C. To this solution
is slowly added 6.9 kilos. of sodium nitrite or rather the corresponding quantity
of technical nitrite in an aqueous solution. After a lapse of 12 hours the clear
solution is gradually brought to boil and is maintained there till the
evolution of nitrogen ceases. The solution is neutralised with carbonate
of calcium, and filtered off from the sulphate of calcium A solution
of m-oxybenzaldehyde-o-sulphonic acid is obtained containing other sul-
phates, which however may be used directly in most cases. In order to isolate the
m-oxybenzaldehyde-o-sulphonic acid the solution is evaporated and the residue
extracted with alcohol of 80%.
From the filtered alcoholic solution the alcohol is distilled off and the remaining
solution of sodium salt of the m-oxybenzaldehyde-o-sulphonic acid is evaporated
to dryness.
Dated
4th day of December 1897
ABEL & IMRAY,.
Agents for the Applicant.

page_text: I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, Chancery
Lane, in the County of London; Chartered Patent Agent, do hereby declare the
nature of this invention (as communicated to me from abroad by The Farbwerke
vormals Meister Lucius and Bruning, of Hoechst a/Main, in the Empire of
Germany, Chemical Manufacturers), and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
A sulphonic acid of m-oxybenzaldehyde has hitherto been unknown.
Meta-oxybenzaldehyde cannot be sulphonated in the usual way, for, if it is
treated with sulphuric acid it undergoes complete decomposition with separation
of carbon.
My correspondents have found that m-oxybenzaldehyde-ortho-sulphonic acid
(COH OH: SO,OH=1:3:6), of great value in the manufacture of acid dyestuffs
of the series of malachite green, may easily be obtained from m-amidobenzalde-
hyde-ortho-sulphonic acid.
The process may for instance be carried out as follows:-
20.1 kilos. of m-amidobenzaldehyde-o-sulphonic acid or the equivalent quantity
of one of its salts are dissolved in about 500 litres of water to which are added
40 kilos. of sulphuric acid of 66° Be. and cooled down to 0° C. To this solution
is slowly added 6.9 kilos. of sodium nitrite or rather the corresponding quantity
of commercial nitrite in an aqueous solution. After a lapse of 12 hours the clear
solution is gradually heated to the boiling point and is maintained at that
temperature till the evolution of nitrogen ceases. The solution is neutralised with
carbonate of calcium, and filtered off from the sulphate of calcium. A solution
of m-oxybenzaldehyde-o-sulphonic acid is obtained which contains other sul-
phates, but may be used directly in most cases. In order to isolate the
m-oxybenzaldehyde-o-sulphonic acid the solution is evaporated and the residue
extracted with alcohol of 80%-
From the filtered alcoholic solution the alcohol is distilled off and the remaining
solution of sodium salt of the m-oxybenzaldehyde-o-sulphonic acid is evaporated
to dryness.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. The herein described manufacture of metaoxybenzaldehyde-ortho-sulphonic
acid by diazotising meta-amidobenzaldehyde-ortho-sulphonic acid in an aqueous
mineral acid solution and boiling the solution thus obtained until the evolution of
nitrogen ceases.
2. Metaoxybenzaldehyde orthosulphonic acid manufactured as above set forth.
Dated this 5th day of September 1898.
ABEL & IMRAY,
Agents for the Applicant.