Improvements in the Manufacture of Aromatic Oxyaldehydes
Year: 1898

page_text: Improvements in the Manufacture of Aromatic Oxyaldehydes,
I, THOMAS RICHARD SHILLITO, of 15, Took's Court, London, EC., Patent Agent, do
hereby declare the nature of this invention, a communication to me from abroad by
Messieurs John Rudolph Geigy & Co., of Basle, Switzerland, Colour Manufacturers,
to be as follows.—
In the Patent Specification No. 17135 of 1898 I have described, as communicated
to me by my foreign correspondents; a new process of introducing the aldehydo
into aromatic amines by treating the same with formaldehyde and an aromatic
hydroxylamine derivative or its sulpho acid.
This reaction however is not only limited to amines, as my correspondents have
found, but it may very successfully be extended to phenols of the benzene and
naphtaline series containing one or several hydroxyl groups and its derivatives of
substitution. My correspondents thus obtain aromatic oxyaldehydes in free form
as well as combined with amines or amidosulpho acids. In order to separate the
aldehydes from these latter combinations it is sometimes necessary to use other
methods than those described in said Specification. Though the benzylidene com-
pounds of the oxyaldehydes when heated up in alkaline solution are decomposed in
the aldehyde and the amine or its amidosulpho acid, it separates, if both com-
ponents possess acid character, neither the one or the other; but if to the alkaline
solution is added a solution of acetate of lead, the oxyaldehyde is precipitated at
once as insoluble salt of lead, whilst the amidosulpho acid remains in solution. The
aldehyde may be separated from the lead by means of acids and purified by
recrystallisation.
The benzylidene compounds of oxyaldehydes with amidosulpho acids may be
decomposed by adding to their neutral very diluted solutions acetate of aniline (or
toluidine) as long as the precipitate is increasing; the insoluble anilide is filtered,
washed, dissolved in diluted bisulphite of sodium or caustic soda lye; the aniline 18
driven off by steam.
The above described process for obtaining oxyaldehydes may be altered in the way
that the hydroxylamine derivative is not allowed to act upon the phenols simul-
taneously with the formaldehyde but start 18 made from the oxybenzyl alcohols,
obtained according to the German Patent Specification No. 85588, by reaction of
formaldehyde upon phenols in alkaline or neutral solution, to which the hydroxyl-
amine solution is added after the solution has been acidulated. The further working
18 the same as above described.

page_text: and 8 kilos. of formaldehyde of 38 per cent Whilst well stirring there is further
gradually introduced 25 kilos of iron filings. After 24 hours the solution is filtered
from a small quantity of impure benzylidene compound; saturated. with common 4
salt and finally the vanilline together with some guaiacol not entered into reaction
extracted by agitating with ether. The filtered benzylidene compound, dissolved. in.
acetate of soda may also be treated with other in order to obtain, some more vanilline.

page_text: As in the preceding example the etheric extract is agitated with bisulphite of soda
and the vanilline can be obtained by acidulation. It crystallises from boiling
ligroine in white needles; melting point 80° C. No formation of
metamethoxylsalicylaldehyde was observed.
5. a-NAPHTOLALDEHYDE.
The mixture of 15 kilos. of nitrobenzene and 45 kilos. of fuming sulphuric acid is
introduced into 250 liters of water, whereupon this solution mixed with 8 kilos. of
formaldehyde of 38 per cent. is, whilst stirring, slowly run into a solution of 14 kilos.
of a-naphtole in 13 kilos. of caustic soda lye of 40° Bé. and 1000 liters of water with
addition of 25 kilos. of iron filings. The a-naphtole separating in small leaves
(lamina) goes again into solution. After from 4 to 5 hours, as soon as the solution
which has in the meanwhile got a deep yellow shade, does not shew any more acid
reaction upon congo paper, acetate of soda is added, whereupon the whole is filtered.
The filtered solution is at once diluted with a large quantity of water, boiled up, and
muriatic acid added, whereupon the a-naphtolaldehyde separates as a crystalline
precipitate. Purified by means of bisulphite, in which the aldehyde dissolves
difficultly, it crystallises in thin filtered needles, soluble in alcohol and ether, scarcely
in water; melting point 1500-151° C.
Dated the 24th der of December 1808
THOMAS R SHILLITO,
15, Took's Court, London, E.C.
Improvements in the Manufacture of Aromatic Oxyaldehydes.
I, THOMAS RICHARD SHILLITO, of 15, Took's Court, London. E.C., Engineer and
Patent Agent, do hereby declare the nature of this invention and in what manner the
same is to be performed-a communication to me from abroad by Messieurs John
Rudolph Geigy & Co., of Basle, Switzerland, Colour Manufacturers-to be particularly
described and ascertained in and by the following statement:-
In the Patent Specification No. 17135 of 1898, communicated to me by my foreign
correspondents, is described a new process of introducing the aldehyde group
into aromatic amines by treating the same with formaldehyde and an aromatic
hydroxylamine derivative or its sulpho acid.
This reaction however is not limited only to amines, as my correspondents have
found, but it may very successfully be extended to phenols of the benzene and
naphtaline series containing one or several hydroxyl groups and its derivatives of
substitution. Aromatic oxyaldehydes are thus obtained in free form as well as
combined with amines or amidosulpho acids In order to separate the aldehydes from
these latter combinations it is sometimes necessary to use other methods than those
described in the aforesaid Patent Specification. Though the benzylidene com-
pounds of the oxyaldehydes when heated up in alkaline solution are decomposed into
the aldehyde and the amine or its amidosulpho acid, it separates, if both components
possess acid character, neither the one or the other, but if to the alkaline solution 18
added a solution of acetate of lead, the oxyaldehyde is precipitated at once as insoluble

page_text: salt of lead, whilst the amidosulpho acid remains in solution. The aldehyde may be
separated from the lead by means of acids and purified by recrystallisation.
The benzylidene compounds of oxyaldehydes with amidosulpho acids may be
decomposed by adding to their neutial very dilated solutions acetate of aniline (or
toluidine) as long as the precipitate is increasing. The insoluble anilide is filtered,
washed, dissolved in diluted bisulphite of sodium or caustic soda lye The aniline is
driven off by steam.
EXAMPLES
1. PARAOXYBENZALDEHYDE.
To 600 liters of an acidulated solution of metasulphoparatolylhydroxylamine 1
(obtained according to said Patent Specification 17135 of 1898) are added 225 kilos.
of formaldehyde of 40 per cent and 28 kilos. of phenol; after two days rest heated up
in order to dissolve the separated benzylidene compound, then acetate of sodium is
added and to the cold solution acetate of aniline as long as the precipitate is still
increasing. This precipitate, the anilide compound of the paraoxybenzaldehyde, 181
filtered, washed, and dissolved in carbonate or bisulphite of soda. The separating aniline
is driven off by steam. When the solution is acidulated the well known paraoxybenz-
aldehyde is precipitated and may be purified by recrystallisation from water.
2. RESORCYLALDEHYDE.
To a cold solution of 60 kilos. of nitrobenzenesulphonate of soda and 22 kilos. of
resorcine in 800 liters of water are added whilst constantly stirring, 50 kilos of iron
filings and then slowly 150 kilos. of muriatic acid (20° Bé.) mixed with 16 kilos of
formaldehyde of 38 per cent. The solution which finally gets a nearly neutra! reaction
is allowed to stand for 24 hours. The benzylidene compound separating by and by 18
filtered, dissolved in hot very diluted caustic soda lye, rapidly filtered (from the iron), :
and precipitated by addition of acetate of lead The lead compound of the
resorcylaldehyde forms a grey precipitate which is filtered, well washed, and decom-
posed by warming up with diluted acids The resoicylaldehyde purified by trans-
formation into its bisulphite compound shews a melting point of 134° C. and is thus
proved to be pure. No formation of resoreyldialdehyde was observed.
3. PROTOCATECHUALDEHYDE
To a cooled solution of 11 kilos. of pyrocatechine and 30 kilos. of nitrobenzene-
sulphonate of soda in 600 liters of water are added, whilst constantly stiriing, 75 kilos.
of concentrated muriatic acid, 8 kilos. of formaldehyde of 38 per cent and 25 kilos. of
of iron filings. After one day's rest at ordinary temperature, the whole solution which
has been filtered from the non and saturated with common salt 18 in a suitable
apparatus extracted with ether. From the etheric extract the aldehyde can be with-
drawn by acidulation, by means of a solution of bisulphite of soda from which it
crystallises. Recrystallised from boiling toluene it shews the known melting point
of 150° C. The small quantity of aldehyde remaining in the extracted mother lye
as benzylidene compound may be obtained by precipitation with acetate of aniline.
Filtration of the insoluble anilide and decomposition of the same according to
Example 1.
4. VANILLINE.
15 kilos, of nitrobenzene are heated up with 45 kilos. of fuming sulphuric acid to
120° 130° C. till a sample does not separate any more nitrobenzene when diluted
with water. The whole mixture is then poured into 600 liters of water and when
cooled to 15° C. has added to it 10 kilos of guaiacol

page_text: fiom a small quantity of impure benzylidene compound, saturated with common salt
and finally the vanilline together with some guaiacol not entered into reaction,
extracted by agitating with ether. The filtered benzylidene compound dissolved in
acetate of soda may also be treated with ether in order to obtain some more vanilline.
As in the preceding example, the etheric extract is agitated with bisulphite of soda
and the vanilline can be obtained by acidulation. It crystallises from boiling ligroine
in white needles Melting point 80° C. No formation of metamethoxylsalicylalde-
hyde was observed,
5. a-NAPHTOLALDEHYDE.
The mixture of 15 kilos. of nitrobenzene and 45 kilos. of fuming sulphuric acid is
introduced into 250 liters of water whereupon this solution mixed with 8 kilos. of
formaldehyde of 38 per cent. ie whilst stirring, run slowly into a solution of 14 kilos.
of a-naphtol in 13 kilos. of caustic soda lye of 40° Bè. and 1000 liters of water with
addition of 25 kilos. of iron filings. The a-naphtol separating in small leaves
(laminae) goes again into solution; after four to five hours, as soon as the solution
which has in the meanwhile got a deep yellow shade does not shew any more acid
reaction upon congo paper, acetate of soda is added, whereupon the whole is filtered.
The filtered solution is at once diluted with a large quantity of water, boiled up and
muriatic acid added whereupon the a-naphtolaldehyde separates as a crystalline pre-
cipitate. Purified by means of bisulphite in which the aldehyde dissolves difficultly, it
crystallises in thin filtered needles, soluble in alcohol and ether, scarcely in water;
melting point 150°-151° C.
According to the same process as described in the foregoing examples my corre
spondents have prepared the following aldehydes :-
m-chloro-p-oxybenzaldehyde, (a-)o-oxy-m-toluylaldehyde, p-oxy-o-toluylaldehyde, p-
oxy-m-toluylaldehyde, B-naphtolaldehyde, o-methoxyl-p-oxybenzaldehyde, orcylalde
hyde, gentismaldehyde, (a-) m-aldehydosalicylic acid. by starting from the following
phenols:-
o-chlorophenol, p-cresol, m-cresol, o-cresol, ẞ-naphtol, resorcinemonomethyl ether,
orcine, hydrochinone, salicylic acid.
Having now particularly described and ascertained the nature of said invention
and in what manner the same 18 to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is:-
1. The manufacture and production of aromatic oxyaldehydes and their products
of substitution. (a) by treating mono or polyatomic phenols of the benzene or
naphtaline series substituted or not substituted in the benzene ring by an element or
an alkyl, methoxyl, ethoxyl, or carboxyl group with formaldehyde and any aromatic
hydroxylamine derivative as such or in statu nascendi or by preference with its
sulpho acid.
(b) by decomposing the benzylidene compounds of the aldehydes with amidosulpho
acids formed beside the free oxyaldehydes by beating the same with diluted acids or
alkalies and by isolating the split off aldehydes as lead salts, or by transforming the
above named benzylidene compounds by addition of aniline or toluidine into their
anilides or toluidides and by decomposing those into amine and aldehyde by heating
with alkalies or bisulphite of soda, substantially as described.
2. The manufacture and production of p-oxybenzaldehyde, m-chloro-p-oxybenz-
aldehyde, (a-) o-oxy-m-toluylaldehyde, p-oxy-o-toluylaldehyde, p-oxy-m-toluyalde-
hyde, a-naphtolaldehyde, -naphtolaldehyde, protocatechualdehyde, vanilline,
resorcylaldehyde, o-methoxyl-p-oxybenzaldehyde, orcylaldehyde, gentisinaaldehyde,
(a-) m-aldehydosalicylic acid from phenol, o-chlorophenol, p-cresol, m-cresol, o-cresol,
a-naphtol, B-naphtol, pyrocatechin, guaiacol, resorcine, resorcinemonomethylether,
oroine, hydrochinone, salicylic acid, substantially as described.
Dated this 23rd day of September 1899.
THOMAS K. SHILLITO,
15, Took's Court, London, E, C.