Manufacture of Amidoalkylsalicylic Acid and Acetamido- alkylsalicylic Acid.
Year: 1893

page_text: Date of Application, 13th Feb., 1893
Complete Specification Left, 1st Nov., 1893-Accepted, 2nd Dec.. 1893
PROVISIONAL SPECIFICATION.
Communicated from abroad by the Firm of KÜCHLER AND BUFF, of Crefeld,
Germany, Manufacturers.]
Manufacture of Amidoalkylsalicylic Acid and Acetamido-
alkylsalicylic Acid.
I, CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery
ane, in the County of London, Chartered Patent Agent, do hereby declare the
ature of this invention to be as follows:-
If
methyl-or-ethyl-salicylic-acid be treated with nitric acid of 1-2 specific weight,
1:2:5, COOH OR: NO,) nitroalkylsalicylic acids will be obtained (Kraus
Ann 150. p. 6, Salkowsky Ann 173. p. 41).
:
By means of reducing agents, such as zinc dust, iron with hydrochloric acid, tin
with hydrochloric acid, tin with acetic acid, alcoholic ammonium sulphide under
pressure, &c., the said nitro products are transformed smoothly into the corre-
sponding amido compounds.
Example. 6 kilos. of nitromethylsalicylic acid are digested for some hours with
10 kilos. of tin and the corresponding quantity of hydrochloric acid, at a tempera-
ture of 100° C., until all has become dissolved.
The solution is then evaporated to dryness, and the residue is again taken up in
water and the tin is removed in the known manner.
The filtrate contains the hydrochloric acid-salt of amidomethyl salicylic acid,
which, after considerable concentration of the solution, solidifies on cooling to a
crystalline magma of fine colourless needles.
The salts are all easily soluble in water, whether on the one hand with mineral
acids or on the other hand with alkalies and alkaline earths.
With iron chloride no colour reaction is produced.
The hydrochlorate of the amido ethylsalicylic acid crystallises also in very
easily soluble needles or four-sided plates. If the solution of the hydrochlorate
be mixed cold with platinum chloride, the platinum double salt separates in fine
and small yellow needles.
B.
The above described amido-compounds or their salts can readily be transformed
by means of glacial acetic acid into the corresponding acetyl compounds. These
acetyl bodies are best obtained if the reduction of the nitro products is directly
effected in glacial acetic acid.
Example. 6 kilos. of uitromethylsalicylic acid and 10 kilos. of tin are mixed cold
with 40 kilos. of glacial acetic acid. The mass becomes heated and boils; the
temperature is maintained for some hours at 100° C., after which the mass is
poured into 400 litres of water, and boiled for some time, after which it is filtered.
From the solution there then separates the acetylamido methyl salicylic acid in
colourless strong crystals, which dissolve with great difficulty in water.
On recrystallising from this solvent the acetyl-product separates in silky lustrous
small needles which melt at 206° to 207° C.
The salts of the alkalies and alkaline earths are easily soluble in water.

page_text: The corresponding ethyl-compound crystallises in lustrous silky needles of a
melting point of 1890 to 190° C.
The above products are suitable for medicinal purposes.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Manufacture of Amidoalkylsalicylic Acid and Acetamido-
alkylsalicylic Acid.
I, CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery
Lane, in the County of London, Chartered Patent Agent, do hereby declare the
nature of this invention and in what manuer the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
If methyl-or-ethyl-salicylic-acid be treated with nitric acid of 1-2 specific weight,
(1:25, COOH: OR: NO,) nitroalkylsalicylic acids will be obtained (Kraus
Ann 150. p. 6, Salkowsky Ann 173. p. 41).
For commercial manufacture it is preferable to use nitric-sulphuric acid.
By means of reducing agents such as zinc dust, iron with hydrochloric acid, tin
with hydrochloric acid, tin with acetic acid, alcoholic ammonium sulphide under
pressure, &c., the said nitro products are transformed smoothly into the corre-
sponding amido compounds.
Example. 6 kilos. of nitromethylsalicylic acid are digested for some hours with
10 kilos. of tin and the corresponding quantity of hydrochloric acid, at a
temperature of 100° C., until all has become dissolved.
The solution is then evaporated to dryness, and the residue is again taken up in
water and the tin is removed in the known manner.
The filtrate contains the hydrochloric acid-salt of amidomethyl-salicylic acid,
which, after considerable concentration of the solution, solidifies on cooling to a
crystalline magma of fine colourless needles.
The salts are all easily soluble in water, whether on the one hand with mineral
acids or on the other hand with alkalies and alkaline earths.
With iron chloride no colour reaction is produced.
The hydrochlorate of the amidoethylsalicylic acid crystallises also in very easily
soluble needles or four-sided plates. If the solution of the hydrochlorate be mixed
cold with platinum chloride, the platinum double salt separates in fine and small
yellow needles.
B.
The above described amido compounds or their salts can readily be transformed
by means of glacial acetic acid acetic acid-anhydride, or acetyl chloride into the
corresponding acetyl compounds. These acetyl bodies are best obtained if the
réduction of the nitro products is directly effected in glacial acetic acid.
Example. 6 kilos. of nitromethylsalicylic acid and 10 kilos. of tin are mixed cold
with 40 kilos. of glacial acetic acid. The mass becomes heated and boils; the
temperature is maintained for some hours at 100° C., after which the mass is
poured into 400 litres of water, and boiled for some time, after which it is filtered.
From the solution there then separates the acetylamidomethylsalicylic acid in
colourless strong crystals, which dissolve with great difficulty in water.
On recrystallising from this solvent the acetyl product separates in silky lustrous
small needles which melt at 206° to 207° C.

page_text: The salts of the alkalies and alkaline earths are easily soluble in water.
The corresponding ethyl compound crystallises in lustrous silky needles of a
melting point of 1890 to 190° C.
The above products are suitable for medicinal purposes.
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. Manufacture of amidoalkylsalicylic acid by treating (1:2:5, COOH OR:
NO,) nitroalkylsalicylic acid with reducing agents, substantially as described.
2. Manufacture of acetylamidoalkylsalicylic acid by boiling either the amido-
alkylsalicylic acid referred to in the first claim, or the corresponding salts thereof,
with glacial acetic acid, acetic acid-anhydride or acetyl chloride, or by directly
effecting the reduction of the nitro-compounds in glacial acetic acid solution,
substantially as described.
Dated this 1st day of November 1893.
ABEL & IMRAY,
Agents for the Applicant.