Manufacture of Ethers of M-oxy-p-amido-benzoic Acid.
Year: 1897

page_text: Date of Application, 17th May, 1897
Complete Specification Left, 12th Feb., 1898-Accepted, 2nd Apr.,
1898
PROVISIONAL SPECIFICATION.
Manufacture of Ethers of M-oxy-p-amido-benzoic Acid.
I, OLIVER IMRAY, of No. 28, 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 Brüning of Hoechst a/ Main, in the Empire of Germany, Chemica!
Manufacturers) to be as follows:-
My foreign correspondents have found that ethers of m-oxy-p-amidobenzoic
acid hitherto unknown may be obtained from m-oxy-p-nitrobenzoic acid by first
reducing and then etherifying it or by reducing the ethers obtained from the
nitro acid. The process is carried on as in the following examples:-
1) Meta-oxy-para-nitrobenzoic acid is heated on the waterbath with concentrated
hydrochloric acid and 1½ times its own weight of tin; the solution thus obtained
is allowed to cool and the crystallising salt is filtered off and obtained pure by
dissolving it in water and precipitating with hydrochloric acid; it forms fine
white needles.
The amido-oxy-acid is precipitated from the aqueous solution of the hydro-
chloride by means of sodium acetate; it crystallises from alcohol in laminae
which melt at 216° C.
To obtain the ester, the hydrochloride or the free acid is warmed in methyl-
alcholic solution with a mineral acid, such as sulphuric acid or hydrochloric acid,
the alcohol is distilled off and then the amido-oxy-methyl ether is separated out
with sodium acetate from the aqueous solution of the residue; it crystallises from
water in needles and melts at 120° C.
The ethyl ether obtained in a similar manner melts at 98° C and crystallises
from chloroform, ligroine in brilliant laminae.
The ethers are easily soluble in alcohol, little soluble in water.
2) Ethyl-para-nitro-meta-oxybenzoate, melting at 84° C., is digested with
hydrochloric acid and stannous chloride at a gentle heat, the hydrochloride of
the amido ester is allowed to crystallise out and is purified by dissolving it in water
and precipitating with hydrochloric acid; it forms crystals easily soluble in
water.
In a similar way the above described amido-oxy-acid methyl-ether is obtained
from meta-oxy-para-nitrobenzoic acid methyl ether of the melting point 91° C.
1907

page_text: COMPLETE SPECIFICATION.
Manufacture of Ethers of M-oxy-p-amido-benzoic Acid.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings,
Chancery Lane, in the County of London, Chartered Patent Agent (but formerly
of No. 28, Southampton Buildings, Chancery Lane, in the County of London), do
hereby declare the nature of this invention (as communicated to me from abroad
by The Farbwerke vormals Meister Lucius and Brüning of Hoechst a/ Main, in
the Empire of Germany, Chemical Manufacturers) and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:—
My foreign correspondents have found that ethers of m-oxy-p-amidobenzoic
acid hitherto unknown may be obtained from m-oxy-p-nitrobenzoic acid by first
reducing and then etherifying it or by reducing the ethers obtained from the
nitro acid. The process is carried on as in the following examples:
1) Meta-oxy-para-nitrobenzoic acid is heated on the waterbath with concentrated
hydrochloric acid and 1 times its own weight of tin; the solution thus obtained
is allowed to cool and the crystallising salt is filtered off and obtained pure by
dissolving it in water and precipitating with hydrochloric acid; it forms fine
white needles.
The amido-oxy-acid is precipitated from the aqueous solution of the hydro-
chloride by means of sodium acetate; it crystallises from alcohol in laminae
which melt at 216° C.
To obtain the ester, the hydrochloride or the free acid is warmed in methyl-
alcoholic solution with a mineral acid, such as sulphuric acid or hydrochloric acid,
the alcohol is distilled off and then the methyl ether of the amido-oxy-acid is
separated out with sodium acetate from the aqueous solution of the residue; it
crystallises from water in needles and melts at 120° C.
The ethyl ether obtained in a similar manner melts at 98° C. and crystallises
from chloroform, ligroine in brilliant laminae.
The ethers are easily soluble in alcohol, little soluble in water.
2) Ethyl-para-nitro-meta-oxybenzoate, melting at 84° C. is digested with
hydrochloric acid and stannous chloride at a gentle heat, the hydrochloride of
the amido ester is allowed to crystallise out and is purified by dissolving it in
water and precipitating with hydrochloric acid; it forms crystals easily soluble in
water.
In a similar way the above described amido-oxy-acid methyl-ether is obtained
from meta-oxy-para-nitrobenzoic acid methyl ether of the melting point 91° C.
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 ethers of m-oxy-p-amidobenzoic acid by
reducing m-oxy-p-nitrobenzoic acid and etherifying it or the converse operation.
2. The ethyl and methyl ethers of m-oxy-p-amido benzoic acid manufactured
as above set forth.