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melting at 17 4 ; it is converted into the nitril on heating with
phosphorus pentoxide. 2 The latter may also be obtained syn-
thetically from orthonitraniline by diazotizing it with hydro-
chloric acid and sodium nitrite, and bringing the compouna
thus obtained into an almost boiling solution of copper sulphate
and potassium cyanide : 3

2C 6 H 4 (NO 2 )N 2 C1 + Cu 2 (CN) 2 = 2C 6 H 4 (NO 2 )CN + N 2 + Cu 2 01 2 .

It crystallizes in needles which are readily soluble in alcohol
and hot water, melt at 109, and sublime when more strongly
heated.

2132 Mctanitrobenzoic acid is best obtained by bringing an in-
timate mixture of one part of previously fused and finely powdered
benzoic acid with two parts of nitre into three or four parts of
sulphuric acid, the mixture being well stirred, and then heating
until the nitrobenzoic acids have separated out as an oily layer. 4
In a well-conducted operation these contain little or no unaltered
benzoic acid. Should this be present in large quantity, it is

1 Claisen and Shad well, Bo: Daitsch. t'hcvi Gcs \ii '^O
J Biirthlein, ibid. x. 1713.
3 Sandmeyer, ibid, xviii. 1492.

* Ernst, loc.cU. ; Leo Liebennann, Ber. Dcutsch. Chcm. Gcs. x. 862 : Widn-
riiann, Ann. C/icm. Pharrn. cxcni. 216.



METANITROBENZOIC ACID. 231



removed by distillation with water, and the product then heated
to boiling with 20 parts of water and neutralized with barium
hydroxide. Barium metanitrobenzoatc crystallizes out on cool-
ing. The mother liquor is evaporated and the residue repeatedly
extracted with small quantities of cold water, the salt of the
ortho-acid being obtained on the evaporation of the solution. A
further crop of crystals of tl:e meta-compound are obtained by
dissolving the residue in 20 parts of boiling water and cooling
the solution, the barium salts of paranitrobenzoic acid, benzoic
acid and styphnic acid remaining in solution.

He tanitro benzoic acid dissolves at 16 5 in 425, and at 100
in 10 parts of water ; on cooling it separates from the solution in
small plates ; it crystallizes from dilute alcohol in monoclinic
tablets, melting at 140 141; when gradually cooled the
melting-point falls to 135 136, but rises again after some
time, or when the remelted acid is allowed to cool rapidly
(Widnmann). It possesses the characteristic property of melting
under hot water; it commences to sublime at temperatures above
100, and its vapour provokes coughing.

Sodium metanitrobenzoate, C 6 H 4 (NO 2 )CO 2 Na -\- 3H 2 O, crystal-
lizes in coarse, colourless or yellowish tablets, and may be
employed for the purification of the crude acid. 1

Barium metanitrobenzoate, (C 6 H 4 .N0 2 .CO 2 ) 2 Ba + 4H 2 O, crys-
tallizes in thin prisms, and is less soluble than the free acid.

Ethyl metanitrolenzoate, C 6 H 4 (NO 2 )C0 2 .C, 2 H 5 , has been pre-
pared by the action of hydrochloric acid on an alcoholic solution
of the acid, by that of alcohol on its chloride, and by the nitra-
tion of ethyl benzoate. It is also formed when ethyl nitrate
and benzoic acid in ethereal solution are treated with sulphuric
acid. 2 It crystallizes in monoclinic prisms, which melt at 41
and have an aromatic smell, boils at 298, and decomposes into
ethylene bromide and metanitrobenzoic acid when heated to
170 200 with bromine. 3

Metanitrobenzoyl chloride, C 6 H 4 (N0 2 )COC1, crystallizes in
pyramids with a diamond lustre or in long, fine prisms, which
melt at 33 34 4 and smell like benzoyl chloride.

Metanitrolenzamide, C 6 H 4 (N0 2 )CO.NH 2 , forms yellow, mono-
clinic needles, and melts at 140 142.

1 Hubner, Ann. Chcm. Pharm. ccxxii. 72.

- Fittica, Journ. Prakt. Clwm.. [2] xvii. 221.

3 'Naumann, Ann, Chcm. Pharm. cxxxiii. 202.

1 n.iispn aivl Thompson, /></. Dcutsch. Chcm. Hc$. xii. 1943.



AROMATIC COMPOUNDS.



Metanitrohippuric acid, C 6 H 4 (NO 2 )CO.NH.CH 2 .CO 2 H. Ber-
tagnini obtained this compound in the year 1851 by taking 6 grms.
of nitrobenzoic acid daily and isolating the nitrohippuric acid from
his very acid urine. He also prepared it by adding sulphuric
acid to a solution of hippuric acid in cold, fuming nitric acid. It
crystallizes from alcohol in silky needles, melting at 162. It is
decomposed by boiling fuming hydrochloric acid into glycocoll
and nitrobenzoic acid. 1

Metanitrobenzonitril, C 6 H 4 (NO 2 )CN, is formed by the action
of phosphorus pentoxide or phosphorus chloride on the amide,
as well as by the nitration of benzonitril and, synthetically, from
metanitraniline in a similar manner to the ortho-compound. It
crystallizes in needles, melting at 117 V 118 . 2

2133 Paranilrobenzoic acid is prepared by the oxidation of
paranitrotoluene with strong nitric acid (Beilstein and Wilbrand ;
Fischer), with potassium dichromate and dilute sulphuric acid 3
or with potassium permanganate. 4

It dissolves in 1200 parts of water at 17, and in 140 parts at
100 without melting, is more readily soluble in alcohol and
crystallizes in yellowish white, lustrous plates, which melt at
238 and sublime in needles.

Barium param'trobenzoate, (C 6 H 4 .NO 2 .C0 2 ) 2 Ba + 5H 2 O, crys-
tallizes in yellow, transparent, monoclinic prisms, which dissolve
in 250 parts of cold and 8 parts of boiling water. It forms an
anhydrous double salt with barium benzoate, (C 6 H 5 .CO 2 ) 2 Ba
+ (C 6 H 4 .NO 2 .CO 2 ) 2 Ba, which crystallizes in large, colourless or
brownish, lenticular aggregates. The calcium salt and calcium
metauitrobenzoate both form double salts with calcium benzoate. &

Ethyl paranitrobenzoatc, C 6 H 4 (NO 2 )CO 2 .C 2 H 5 , forms asym-
metric plates, which melt at 57, and are converted by heating
with ammonia into paranitrobcnzamide, C 6 H 4 (NO 2 )CO.NrT 2 ,
which crystallizes in needles melting at 197 198.

Paranitrobenzoyl chloride, C 6 H 4 (NO 2 )COC1, boils at 202
205 under a pressure of 105 mm., and crystallizes from petro-
leum spirit in fine needles, melting at 7o. 6

1 Ann. Chem. Pharm. Ixxviii. 100 ; Schwanert, ibid. cxii. 69 : Conrad. Journ.
Prakt. Chcm. [2] xv. 254.

2 Beilstein, Ann. Chcm. Pharm. cxlvi. 336 ; Engler, ibid, cxlix. 297 ; Schoppf,
Bcr. Deutsch. Chem. Ges. xviii. 1063.

3 Beilstein and Geitner, Ann. Chcm. Pharm. cxxxix. 335 : Kbrner, Zeikchr.
Chcm. 1869, 635 ; Rosenstiehl, ibid. 1869, 701.

4 Michael and Norton, Bcr. Deutsch. Chcm. Gcs. x. 580.

5 Sfdkowsky, ibid. ix. 24 ; x. 1257.

8 Gevekoht, Ann. Chem. Pharm. ccxxi. 335.



PAKAN1TROHIPPURIC ACID. 233

Paranitrobcnzonitril, C 6 H 4 (NO 2 )CN, is obtained by heating
the amide with phosphorus pentoxide, 1 as well as by diazotizing
paranitraniline and pouring the solution into a well agitated
solution of potassium cuprous cyanide in potassium cyanide,
heated to 90. 2 It crystallizes from alcohol in plates, and
sublimes on heating in long, feathery crystals, melting at 147.

Paramtrohippuric acid, C 6 H 4 (NO 2 )CO.NH.CH 2 .CO,H, is
formed, together with paranitrobenzoic acid, by the passage of
paranitrotoluene through the system in the dog, and is found in
the urine combined with urea. It crystallizes from hot water in
orange-red prisms, melting at 129 . 3

So-called isomeridcs of the three nitrdbenzoic acids. It was
early stated by Mills that four mononitrobenzoic acids exist, and
Fittica thought that he had prepared five new isomerides,
differing from the three already mentioned in their melting
points, three of them being also distinguished by their citron-
yellow colour. He obtained these substances " by peculiar
methods, which chiefly consisted in avoiding with the greatest
care all trustworthy modes of purification," 4 but the researches
of others have shown that his compounds do not exist. 5 The
melting points and physical properties of the nitrobenzoic acids,
like those of benzoic acid itself, are greatly altered by very
small quantities of admixed impurities ; when benzoic acid is
nitrated, small amounts of the dinitrobenzoic acids are always
formed in addition to the three mononitrobenzoic acids, and
the product also contains benzoic acid and styphnic acid (trini-
troresorcinol), the latter of which gives it its yellow colour.

Bodewig found that three of Fittica's new acids are simply
impure forms of metanitrobenzoic acid, which he obtained from
them by crystallization ; the two others gave no measurable
crystals ; he also observed that this acid, besides its stable form,
exists in two unstable modifications, which also crystallize in the
monoclinic system, but differ from the stable form in their
crystallographic constants. Their crystals soon become opaque,
from the formation of the stable form, a change which takes
place in one of the unstable modifications even when its crystals
are allowed to remain in the mother liquor. He further

Fricke, Bcr. Dcutsch. Chrm. Gcs. vii. 1322.
Sandmeyer, ibid, xviii. 1492.
Jalle. ibid. vii. 1673.
Kfkule, Lclirb. Org. CJwm. iii. 554.
Erlenmeyer and "Widnmann, Ber. Dcutsch. Chem. Gcs. viii. 392 ; Griess,
viii. 526 ; Ladenljurtf, ibid. viii. 535 and 853 ; Salkowsky, ibid. viii. 636 ;



t. v. 26 ; aenljurtf, ibid. viii. 535 and 853 ; Saowsy,
Uebennaun, ibid. x. 1036 ; Clans, ibid. xiii. 891 ; Fittica, ibid.



xiii. 1537.



234 AROMATIC COMPOUNDS.



proved their identity by converting them into the ethyl ether. 1
Fittica's acids, therefore, have no more real existence than
salylic acid (p. 158).



DINITROBENZOIC ACIDS, C 6 H 3 (NO 2 ) 3 CO 2 H.

2134 The appended numbers indicate the position of the
nitroxyls when that of the carboxyls is 1.

a-Dinitrobenzoic acid, (2 : 5), was obtained by Griess, together
with the two following and styphnic acid, by heating one part
of orthonitrobenzoic acid with ten parts of a mixture of equal
amounts of fuming sulphuric and nitric acids. 2 It is slightly
soluble in cold water, and on evaporation separates out in prisms;
it is deposited from the hot saturated solution as a yellowish oil,
which solidifies in needles, melting at 177. It is reduced to
a-diamidobenzoic acid by tin and hydrochloric acid.

Barium a-dinitrobenzoate, (C 6 H 3 (N0 2 ) 2 C0 2 ) 2 Ba + 4H 2 O, forms
long, six-sided plates, which are slightly soluble in cold, more
readily in hot water.

@-Dinitrobenzoic acid, (2 : 4), is also formed by the oxidation
of ordinary dinitrotoluene with fuming nitric acid, 3 and by the
nitration of paranitrobenzoic acid. 4 It melts in hot water and
crystallizes from it in long, lustrous, brittle needles, or on spon-
taneous evaporation in large, rhombic tablets or prisms, which
melt at 179 and have a bitter taste. Tin and hydrochloric
acid convert it into metadiamidobenzene, carbon dioxide being
eliminated.

Barium fi-dinitrobenzoate, (C 6 H 3 (N0 2 ) 2 C0 2 ) 2 Ba + 3H 2 O, is
tolerably soluble in cold water and crystallizes in white, rhombic,
or six-sided tablets.

y-Dinitrobenzoic acid, (2 : 6), is very freely soluble in boiling
water, crystallizes in fine, matted, white needles, melts at 202,
and, like its isomerides, has a very bitter taste. It decomposes
on distillation into carbon dioxide and metadinitrobenzene, and
on reduction yields metadiamidobenzene.

Barium y-dinitrobenzoate, (C 6 H 3 (NO 2 ) 2 C0 2 \Ba + 2H 2 O, is
very readily soluble in water and crystallizes in needles.

1 Ber. Deutsch. Chcm. Ges. xii. 1983 ; Zeitschr. Knjst. iv. 58.
3 Bcr. Deutsch. Chcm. Ges. vii. 1223.

3 Tiemann and Judson, ibid. iii. 223 ; Wurster, ibid. vii. 148.

4 Clans and Halbcrstadt, ibid. xiii. 815 ; Stromeyer, .4?;?!. Chcm. Phann.
ccxxjL 79.



inn.



THE DINITROBENZOIC ACIDS. 235

S-Dinitrolenzoic acid, (3 : 5), or Ordinary dinitrdbenzoic acid,
was first prepared by Cahours : l it is obtained by heating ben-
zoic acid 2 or metanitrobenzoic acid 3 with a mixture of nitric
and sulphuric acids, or by oxidizing symmetric dinitrotoluene
with chromic acid 4 or nitric acid (Hiibner).

In order to prepare it, 20 grms. of benzoic acid are dissolved
in 180 grms. of concentrated sulphuric acid, one-third of the
volume of fuming nitric acid added, and the whole heated nearly
to boiling for four hours and then poured into two volumes of
cold water ; a yield of 30 grms is obtained. 5

It crystallizes from hot water in thin, quadratic tablets, and
from alcohol in prisms, which melt at 204 205, and sublime
in needles. On reduction it yields 8-diamidobenzoic acid. Its
salts detonate violently when heated.

Barium S-dinitrolenzoafe, (C 6 H 3 (NO 2 ) 2 C0 2 ) 2 Ba + H 2 O, forms
small crystals, readily soluble in hot water (Hubner).

c-Dinitrolenzoic acid, (3 : 4), is formed at, the same time as the
/3-acid by the action of a mixture of nitric and sulphuric acids
on paranitrobenzoic acid. It has an intensely bitter taste, is
only slightly soluble in cold water, fuses under hot water and
crystallizes from it in stellate groups, melting at 161. These
crystals sublime at a higher temperature, and detonate violently
when heated on platinum foil. 6

Barium e-dinitrobenzoalt, (C H 3 (NO 2 ) 2 C0 2 ) 2 Ba + 4H 2 0, forms
a white, radiating crystalline mass.



TRINITROBENZOIC ACID, C 6 H 2 (NO 2 ) 3 C0 2 H.

2135 This compound is obtained by heating trinitrotoluene to
100 with fuming nitric acid for a week. It crystallizes from
hot water in rhombic prisms, melts at 190 and sublimes at a
higher temperature. 7

1 Ann. Chem. Pharm. Ixix. 241.

2 Michler, ibid, clxxv. 152.
Muretow, Zeitschr. Chem. 1870, 641.
Stadel, Ber. D>:utsch. Chem. Gcs. xiv. 902.
Hubner, Ann. Chem. Pharm. ccxxii. 72.

Glaus and Halberstadt, Ber. Deutsch. Chem. Gfcs. xiii. 815.
Tieinann and Judson. ibid. iii. 224.



236 AROMATIC COMPOUNDS.



CHLORONITROBENZOIC ACIDS, C 6 H 3 C1(N0 2 )CO 2 H.

Cl : N0 2 Melting-point.

a) 2:5 silky needles or rhombic tablets 1 . . 164 165

/3) 3:6 prisms 2 137 138

<y) 3:2 long, thin needles or six-sided tablets 3 235

3) 3:5 small needles 4 147

e) 4:3 small needles 5 179 C 180

) 2:4 readily soluble crystals 6 136 137

The first three of these acids have been obtained by the
nitration of ortho- and meta-chlorobenzoic acid. The fourth
acid is prepared from the corresponding amidonitrobenzoic acid
and the fifth by the nitration of parachlorobenzoic acid ; this
compound and the last have also been obtained by the oxida-
tion of the corresponding chlorouitrotoluenes. Since the -acid
melts at the same temperature as the /8-acid, they were
considered to be identical, but this is not the case, as the
-acid is derived from paranitrotoluene, and can be converted
into orthochlorobenzoic acid.



BROMONITROBENZOIC ACIDS, C 6 H 3 Br(NO 2 )C0 2 H.

Br : NO. 2 Melting-point.

a) 2:5 long needles 7 177 178

/3) 3,6 monoclinic prisms 8 140 140

y) 3:2 monoclinic crystals 9 ....... 250

8) 4:3 small plates or needles 10 199

e) 3:5 long needles or thin, six-sided tablets n 161

) 2:4 long needles 12 163 164

1 Kekule, Ann. Chem. Pharm. cxvii. 135 ; Hiibner, Zeitschr. Chem. 1886, 614 ;
Htibner and Biedermann, Ann. Chcm. Pharm. cxlvii. 263 ; Wilkens and Rack,
ibid, ccxxii. 192.

Ulrich, ibid, ccxxii. 95. 3 Ibid.

Grube, Ber. Deutsch. Chem. Ges. x. 1703.

Hiibner and Biedermann ; llaveill, Ann. Chcm. Pharm. ccxxii. 182.
Wachendorff, ibid, clxxxv. 275..

Burghard, Ber. Deutsch. Chcm. Ges. viii. 560 ; Rahlis, Ann. Chcm. Pharm.
cxcviii. 109 ; Scheufelen, ibid, ccxxxi. 181.

8 Hiibner, Only and Philipp, ibid, cxliii. 233 ; Hiibner and Meeker, Zeitschr.
Chem. 1867, 565 ; Hiibner and Petermann, Ann. Chem. Pharm. cxlix. 132 ;
ccxxii. 101. 9 Hid,

10 Ibid. ; Raveill, Ber. Deutsch. Chem. Ges. x. 1707 ; Ann. Chcm. Pharm.
ccxxii. 177 ; Scheufelen.
11 Hesemann and Kohler, ibid, ccxxii. 166. 13 Scheufelen.



OETHO-AMIDOBENZOIC ACID.



The first is formed by the nitration of orthobromobenzoic
acid, as well as by the oxidation of the corresponding bromo-
nitrotoluene, and yields 8-dibromobenzoic acid when the
nitroxyl is replaced by bromine. The following two have been
prepared from metabromobenzoic acid and are converted into
anthranilic acid by reduction (Part III., p. 56). The S-acid is
obtained from parabromobenzoic acid and from metanitrobromo-
toluene, the e-acid from the corresponding amidonitrobenzoic
acid, and the -acid by the oxidation of the corresponding
bromonitrotoluene.



IODONITROBENZOIC ACIDS, C ( .H 3 I(NO 2 )C0 2 H.

I : NO 2 Melting-point

a) 3:2 slightly soluble crystals * 235

/3) 3:6 readily soluble, melts under water 2 . . . 179

7) 3:4 readily soluble, does not melt under water 3 192

8) 4:3 readily soluble in alcohol, very slightly in

water 4 210

The first three are formed by the nitration of meta-iodobenzoic
acid, and the last one from para-iodobenzoic acid.



MONAMIDOBENZOIC ACIDS, C 6 H 4 (NH2)C0 2 H.

2136 Ortho-amidobenzoic acid. Fritzsche, in his research on
aniline, mentioned that the product of the first action of potash
on indigo is a characteristic acid, which he subsequently obtained
pure by employing indigo-blue in the place of crude indigo.
He determined its composition, and his results were confirmed
by the remarkable decomposition which occurred on heating.
"Anthranilic acid decomposes when it is heated to a tempera-
ture just exceeding its melting-point into carbon dioxide, which
is given off as a gas, and aniline." 5

Liebig looked upon this research as of exceptional interest,
and its confirmation appeared to him to be so important and

1 Cunze and Hiibner, ibid, cxxxv. 106 ; Grothe, Journ. Prakt. Chcm. [2] xviii.
324. 2 Ibid. 3 Ibid.

* Glassner, Bcr. Dcutsch. Chcm. Ges. viii. 562.
5 Journ. Prakt. Chcm. xxiii. 67 ; Ann. Chcm. Pharm. xxxix. 76.



238 AROMATIC COMPOUNDS.



necessary, that he instituted further investigations, which cor-
roborated the results obtained by Fritsche. 1 At the same time
he discovered an excellent method for the preparation of
anthranilic acid, which will be described below.

Gerland subsequently showed that the acid in question is
isomeric with benzamic acid (metamidobeuzoic acid). 2 Hiibner
and Petermann succeeded in preparing anthranilic acid syn-
thetically from benzoic acid ; by the nitration of metabromo-
benzoic acid, they obtained two isomeric nitrobromobenzoic
acids, C 6 H 3 Br(N0 2 )C0 2 H, both of which yielded anthranilic
acid on reduction (Part III., p. 56). It may be more simply
obtained by the reduction of orthonitrobenzoic acid with tin and
hydrochloric acid ; 3 the tin is precipitated with s\ilphuretted
hydrogen and the filtrate evaporated to dryness, the residue
treated with an excess of ammonia and the solution then
acidified with acetic acid. The greater portion of the anthra-
nilic acid crystallizes out ; the remainder is then obtained as the
copper salt by the method described below.

Sandmeyer observed that almost half of the nitrobenzoic
acid is converted into salicylic acid on reduction with tin and
hydrochloric acid. 4

In order to prepare it from indigo, the crude material is finely
powdered and boiled for ten hours with ten times its amount of
strong caustic potash solution, a small quantity of manganese
dioxide being occasionally added, and the original volume of the
solution maintained throughout the operation by the repeated
addition of small quantities of water. The solution is then
neutralized with sulphuric acid, freed from most of the potassium
sulphate by crystallization and evaporated to dryness. Potassium
anthranilate is extracted from the residue by alcohol and is then
converted into the copper salt, which is obtained as a light green
precipitate by distilling off the alcohol, acidifying with acetic
acid and adding copper acetate or sulphate ; the free ' acid is
obtained from this by the action of sulphuretted hydrogen. 5
Bottinger found that the only definite compound formed in this
reaction, in addition to 28 per cent, of anthranilic acid, is formic
acid: 6

C 16 H 10 N 2 2 + 20 + 4H 2 = 2C 7 H 7 N0 2 + 2CH 2 2 .



Ann. Chem. Pharm. xxxix. 91. 2 Ibid. Ixxxvi. 143.
Beilstein and Knhlberg, Ann. Chem. Pharm. clxiii. 138.
Ber. Deutsch. Chem. Oes. xviii. 1494.
Hiibner and Petermann, Ann. Clicm. Pharm. cxlix. 142.
Ber. Deutsch. Chem. Ges. x. 269.






PROPERTIES OF ORTHO-AMIDOBENZOIC 1 ACID. 239



Ortho-amiJobenzoic acid dissolves in about 250 parts of cold,
more readily in hot water, and readily in alcohol. The solution
has a sweet taste, but is acid to litmus paper, and shows a blue
fluorescence when the acid is pure. It crystallizes in small
plates, or on the gradual evaporation of its solution, in rhombic
needles, melts at 145, and sublimes when carefully heated, but
decomposes into carbon dioxide and aniline when distilled, more
completely when mixed with powdered glass (Liebig). On
treatment with sodium amalgam, benzoic acid and ammonia are
formed (Hiibner and Petermann) :

C 6 H 4 (NH 2 )C0 2 H + 2H = C 6 H 5 .C0 2 H + NH 3 .

Most of its metallic salts crystallize well.

Ortho-amidobenzoic acid hydrochloride, C 7 H 7 N0 2 HC1, is readily
soluble in water and alcohol, slightly in ether, and crystallizes in
needles or four-sided prisms, melting at 191; its solution is not
precipitated by platinum chloride.

Formortho-amidobenzoic acid, 2C 6 H 4 (NH.CHO)C0 2 H + H 2 O,
is obtained by heating ortho-amidobenzoic acid with formic acid,
and crystallizes from chloroform in fine, matted needles, which,
after drying, form a light, very readily electrified mass, and melt
at 108. When it is heated with phosphorus pentoxide, phenyl
carbamine is formed. 1

Acetortho-amidobenzoic acid, C H 4 (NH C. 2 H 3 O)C0 2 H, is formed
by the oxidation of acetorthotoluide with potassium perman-
ganate, 2 and by heating a mixture of equal molecules of
anthranilic acid and acetic anhydride. 3 It is slightly soluble in
cold, readily in hot water, and crystallizes from acetic acid in
flat, rhombic needles, which melt at 179 180.

Diacetortho-amidobenzoic acid, C 6 H 4 N(C 2 H 3 0) 2 C0 2 H, is ob-
tained by boiling anthranilic acid with an excess of acetic
anhydride, and forms crystals, melting at 220 (Bedson and
King).

Benzortho-amidobenzoic acid, C 6 H 4 (NH.CO.C 6 H 5 )CO 2 H, is
formed by the action of benzoyl chloride on anthranilic acid
and by the oxidation of benzoylorthotoluide. It crystallizes
from alcohol in long needles, melting at 182 . 4

1 v. Meyer and Bellniann, Journ. Prakt. Chem. [2] xxxiii. 24.
Bedson and King, Ber. Dcutsch. Chem. Ges. xiv. 263.

3 Jackson, ibid. xiv. 886.

4 Briickner, Ann. Chem. Pharm. ccv. 134.



240 AROMATIC COMPOUNDS.

Ortho-amidobenzamide, C 6 H 4 (NH 2 )CO.NH 2 , is formed when
anthranilcarboxylic acid is dissolved in aqueous ammonia :

/CO /CO.NH 2

C 6 H 4 < | +NH 3 = C 6 H 4 < +C0 2 .

\ N.C0 2 H \NH 2

It crystallizes from hot water in nacreous plates, and from
chloroform in large, white plates, melts at 108, and boils with
slight decomposition at about 300. It is converted into ortho-
amidobenzoic acid by acids and alkalis. 1

Ortho-amidobenzonitril, C 6 H 4 (NH 2 )CN, is obtained by the
action of tin and hydrochloric acid on orthonitrobenzonitril ; it
crystallizes in yellowish needles, melts at 103, and forms readily
soluble salts. 2

2137 j4.nthrct.nil, C 7 H 5 NO, is formed by the action of tin on a
solution of orthonitrobenzaldehyde in glacial acetic acid, and is
a colourless, oily liquid, which has a characteristic, penetrating
smell, is volatile with steam, and commences to boil at 210 215 C ,
the greater portion of it being decomposed. It rapidly becomes
brown and resinous when exposed to the air or to light. It is a
very feeble base, and combines with mercuric chloride to form the
compound C 7 H 5 NO + HgCl 2 , which crystallizes in fine needles
and is readily soluble in alcohol and hot water, but on heating
with a solution of potassium chloride, is resolved into its
constituents. 3

Anthranil is converted into anthranilic acid by the action of
alkalis :

CO CO.OH



When heated with ammonia and ferrous sulphate it is con-
verted into orthonitrobenzaldehyde, while anthranilcarboxylic
acid is formed when it is heated with ethyl chloroformate :



/CO /CO

<+ COC1(OC = C 6 H/ I



+ C 2 H 6 C1.
N.CO.OH



This compound crystallizes from hot water in fine needles,
which decompose into carbon dioxide and anthranil at 230. It

1 Kolbe, Journ. Prakt. Chem. [2] xxx. 475.

2 Barthlein, Ber. Dcutsch. Chem. Get. x. 1713.

3 Fiiedlanderand Henriques, ibid. xv. 2105.






BENZOYLANTHRAN1L. 241

dissolves in dilute caustic soda, forming a solution which possesses
a splendid blue fluorescence ; this, however, soon disappears,
anthranilic acid being formed. Anthranilcarboxylic acid is also
obtained by the oxidation of isatin, and will be more fully
described along with this substance.

Bcnzoylanthranil is readily obtained by the action of benzoyl



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