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deposit more gradually, it forms long, transparent needles.
100 parts of water at 23'5 dissolve 17'7 parts; it is still more
readily soluble in alcohol.

Acid paratoluidine oxalate, C 7 H 9 N, C 2 O 4 H 2 , crystallizes in
rhombic needles or prisms, 0'87 parts of which dissolve in 100
parts of water at 14 ; alcohol takes up even less.

Paratoluidine phenate, C 7 H 9 N, C 6 H 6 O, crystallizes from petro-
leum ether in long needles melting at 3M. 2

Methylparatoluidine, C 6 H 4 (CH 3 )N(CH 3 )H, is obtained by
passing methyl chloride into heated paratoluidine. The pro-
duct is extracted with ether, the paratoluidine hydrochloride
formed being left undissolved. Any unaltered paratoluidine is
precipitated by dilute sulphuric acid, and the ether evaporated,
a mixture of methyltoluidine and dimethyltoluidine being thus
obtained. The former is converted by the action of acetic

* Ann. Chem. Pharm. clvi. 73.

- G. Dyson, Journ. Chcm. Soc. 1883, i. 468.



METHYLTOLUIDINES. 65

anhydride into acetmethylparatoluide, C 6 H 4 (CH 3 )N(C 2 H 3 O)CH 3 ,
which crystallizes from a mixture of ether and alcohol in large
plates melting at 83. Pure methylparatoluidine is then ob-
tained by boiling this compouad with hydrochloric acid and
decomposing the hydrochloride with caustic soda. 1 It can be
even more simply separated by means of its nitrosamine, in the
same way as its isomeride in the ortho-series. (Monnet, Reverdin
and Noiting.) It is a liquid which boils at 208 and possesses
an aromatic odour.

Nitrosomethylparatoluidine, C 6 H 4 (CH 3 )N(CH 3 )NO, crystallizes
from a mixture of ether and alcohol in large, well-formed prisms,
melting at 54.

Dimethylparatoluidine, C6H 4 (CH 3 )N(CH 3 ) 2 . By the action of
methyl iodide on paratoluidine, Thomsen obtained trimethyl-
paratolylammonium iodide, C 7 H 7 N(CH 3 ) 3 I, which forms white
crystals, and converted it by means of moist silver oxide into the
hydroxide, which yielded the base on distillation ; 2 it is a liquid,
which has a characteristic aromatic odaur and boils at 208.

Boiling-point.

Ethylparatoluidine, C 7 H 7 N(C 2 H 5 )H, 'liquid 217
Di-ethylparatoluidine,s C 7 H 7 N(C 2 H 5 ) 2 229

Phenylparatoluidim, or Fhenylparatolylamine, C 7 H 7 N(C 6 H 5 )H,
was obtained by Hofmann by the dry distillation of toluidine-
blue or tritolylrosaniline, 4 while de Laire, Girard, and Chapoteau
prepared it by heating aniline with toluidine hydrochloride or
toluidine with aniline hydrochloride. In both cases the product
is a mixture of diphenylamine, phenyltoluidine, and ditolylamine,
v> liich cannot be readily separated by fractional distillation. 6

It is also formed when equal molecules of phenol and para-
toluidine, or paracresol and aniline, are heated with an excess of
zinc chloride for twenty hours to 260 30Q . 6 Phenylparatolui-
dine crystallizes readily from alcohol in long, silky needles, melts
at 87 and boils at 334-0 : Its salts, like those of diphenyl-
amine, are decomposed by water, and it gives a fine blue colour-
ation with concentrated nitric acid. When fused with mercuric
chloride or hexchlorethane, a splendid violet colouring matter
is formed.

1 Thomsen, Bcr. Deutsch. Cliem. Ges. x. 1582.

2 See also Hiibner, Tolle and Athenstadt, Ann. Chcm. Pharm. ccxxiv. 336.

3 Morley and Abel, ibid, xciii. 313. * Ibid, cxxxii. 291.
D P.uch, Jier. D'uitch. Chcm. Ges. xvii. 2034.

6 Morley and Abel, Ann. Chcm. Pharm. cxl. 347.
VOL. III. PART IV. F



AROMATIC COMPOUNDS.



Diparatolylamine, (C 6 H 4 .CH 3 ) 2 NH, is obtained by heating
paratoluidine with its hydrochloride to 210 240. It forms
long needles melting at 79 , 1 boils at 355 360, and is coloured
yellow by nitric acid. Its salts are decomposed by water.

Diparatolylnitrosamine, (C 6 H 4 .CH 3 ) 2 N(NO), is deposited from
petroleum-ether in golden-yellow, hollow, rhombic crystals,
melting at 100 101. When it is gradually added to
well-cooled fuming nitric acid, Jiexnitrodi^iaratolylamine,
(C 6 H(NO 2 ) 3 CH 3 ) 2 NH, is formed; this crystallizes in small
yellow pyramids which melt at 258, and are slightly soluble
in the usual solvents. 2

Acctparatoluide, C C H 4 (CH 3 )N(C 2 H 3 O)H, was first observed
by Riche and Be"rard in the preparation of aniline oil by means
of iron and acetic acid, and then prepared by repeated
distillation of paratoluidine with acetic acid. 3 Arndt and
Stadeler obtained it in the same way from crude aniline, and
separated it from the acetanilide formed by dissolving the
mixture in acetic acid and precipitating the less soluble acet-
toluide with water. 4

Acetparatoluide is dimorphous ; on the gradual evaporation of
its alcoholic solution it separates in monoclinic crystals ; when a
hot solution is allowed to cool, however, it crystallizes in rhombic
needles. 5 It melts at 147 6 , and boils at 307 . 7 1,000 parts of
water dissolve 0'56 parts at 65, and 0'886 parts at 22.

Paratolyl carbamide, (C 7 H 7 )NH.CO.NH 2 . Sell prepared this
compound by the action of potassium cyanate on toluidine
sulphate, 8 and Steiner obtained it, together with ditolylguanidine,
by treating fulminate of mercury with paratoluidine. 9 It is
readily soluble in hot water, and crystallizes in thick needles
melting at 172 . 10

Diparatolyl carbamide, (C 7 H 7 NH) 2 CO, is formed on the
distillation of the compound just described (Sell), or when it is
heated to 150 170 with paratoluidine. 11 It is also obtained
when carbonyl chloride is passed into a solution of paratoluidine
in chloroform. 12 It is insoluble in water, and crystallizes from

Ber. Dcutsch. Chcm. Gcs. vi. 446.

Cosack, ibid. xiii. 1092 ; Lehne, ibid. xiii. 1544.

Ann. Chem. Pharm. cxxix. 77.

Chem. Ccntralbl. 1864, 707. 5 Panebianco, Jahresber. 1878, 678.

in MHT, and tfallach, Ann. Chem. Pharm. cliv. 302

l.filstem ami Kuhllwrs, ibid. clvi. 74.

Beilstein and Kuhlberg, ibid, cxxvi. 157.

s. viii. 519. 10 Cosack, ibid. xii. 1450.

12 Michler, ibid. ix. 710



PARATOLYL URETHANE. 07

hot alcohol in flat needles, which resemble those of benzoic acid
and melt at 256.

Paratolyl urethane, or Ethyltolyl carbamate, (C 7 H 7 )NH(CO)
(OC 2 H 5 ), is obtained by the action of chlorocarbonic ether on
paratoluidine in ethereal solution. It is insoluble in water
and crystallizes from alcohol in long prisms, melting at 52.

Paratolyl carbimide, CO.N.C 7 H 7 , is obtained by the distillation
of the carbamic ether with phosphorus pentoxide, as a strongly
refractive liquid boiling at 185; its vapour possesses a penetrating
odour and causes a flow of tears. 1

Paratolyl thiocarbamide, (C 7 H 7 )NH(CS)NH, is formed when
paratoluidine hydrochloride is heated with ammonium thio-
cyanate, 2 and by the combination of paratolyl mustard oil with
ammonia. 3 It is slightly soluble in cold water and crystallizes
from hot alcohol in small tablets or thick needles melting
at 182.

Diparatolyl thiocarbamide, (C 7 H 7 .NH) 2 CS, crystallizes from hot
water in large, pointed prisms, melting at 176. 4

Paratolyl thiocarbimide, or Paratolyl mustard oil, CS.N.C 7 H 7 .
Hofmann obtained this compound by heating the substance just
described with phosphorus pentoxide. 5 In order to prepare it;
paratolyl thiocarbamide is heated to 160 with 30 per cent,
sulphuric acid. 6 It crystallizes from ether in long, white needles,
melts at 26, and boils at 237. While both its isomerides
possess the characteristic pungent odour of the mustard oils, the
smell of paratolyl thiocarbimide resembles that of oil of aniseed.

Like other thiocarbimides it combines with ammonia, the
amines, and the aromatic amido-bases to form compound
thio- ureas.



HALOGEN SUBSTITUTION PRODUCTS
OF THE TOLUIDINES.

2050 A very large number of these has been prepared, but
only the mono-substitution products will be here described.

1 Hofmann, Bcr. Dcutsch. Chcm. Ges. iii. 656.

2 Clcnnont and Wehrlin, Bull. Soc. Chim. xxvi. 126.

3 Staats, B-r. Deutsch. Chcm. Ges. xiii. 136.

4 Sail, Ice. cit. ; Maly, Jahresber. 1869, 637.

5 Ji.:r. Dcutsch. Chc.m. Ges. i. 173.

< ; Licbcrmann and Natanson, Ann. Chcm. Pharm. ccvii. 160.

F 2



AROMATIC COMPOUNDS.



CHLOROTOLUIDINES, C 6 H 3 C1(CH 3 )NH 2 .

Melting- Boiliug-

^H NH Cl point. point.

Y 5 2 "'4 small plates 1 29'5

1 3 4 thin plates 2 30

143 liquid 3 222

1 4 2 crystals 4 26 237-238'5



BROMOTOLUIDINES, C 6 H 3 Br(CH 3 )NH 2 .

CH 3 : NH 2 : Br

123 liquid 5

1 2 4 plates 32 253-2r>7

1 2 5 rhombohedra 7 58 240

134 prisms 8 32

! 35,, 9 36 255 260

1 3 6 10 78-5 240

1 4 2 n 26

1 43,, 12 8 240

Neville and Winther have also prepared dibromotoluidines
together with higher substitution-products, by methods which
give a knowledge of their constitutions. 13



IODOTOLUIDINES, C 6 H 3 I(CH 3 )NH 2 .

CH, : NH S : I

124 needles 14 . .... 49
1 3 4 small plates 15 189

1 Beilstein and Kuhlber*, Ann. Chem Pharm. clvi. 81 ; clviii. 337.

2 Gattermann and Kaiser, Ber. Deutsch. Chem. Ges. xviii. 2599.

8 "Wroblevsky, Ann. Chem. Pharm. clxviii. 153 ; Bcr. Deutsch. Chem. Ges. vii.
1062.
* Lellmann, ibid. xvii. 534.

5 Neville and Winther, ibid, xiii 1945.

6 Korner, Zeitschr. Chem. 1869, 636 ; Hiibner and Wallach, Ann. Chem. Pharm.
cliv. 298 ; Heynemann, ibid, clviii. 340 ; Hiibner and Roos, Ber. Dutsch. Chem.
Ges. vi. 799.

7 Wroblevsky ; Crete, Ann. Chem. Pharm. clxxvii 249.

8 Neville and Winther, Ber. Deutsch. Chem. Ges. xiii. 972.

9 Wroblevsky, Ann. Chem. Pharm. cxcii. 192, 203 ; Neville and Winther.

10 Wroblevsky ; Neville and Winther.

11 Neville and Winther, Bcr. Dntisch. Chem. Ges. xiv. 418.

12 Wroblevsky, Ann. Clinn. Pharm. clxviii. 153.

13 Bcr. Deutsch. Chem. GW. xiv. 419 14 Heynemann, loc. cit.
13 Glassner, ibid. viii. 561.



NITROTOLUIDINES.



NITROTOLUIDINES, C fl H 3 (CH 3 )NH 2 (NO 2 ).

2051 The numbers subjoined refer to the positions of the
side-chains in the order given in the formula.

a-Orthonitro-orthotoluidine (1:2:6) is formed by the partial
reduction of the orthodinitrotoluene melting at 60 61. It is
slightly soluble in water, more readily in alcohol, and crystallizes
in long, light yellow needles melting at 90 91; it may
be converted into orthonitrotoluene by the elimination of the
amido-group. 1

f3-0rthonitro-orthotolu'idine (1:2:3) is obtained as a by-
product in the preparation of the compound next described, and
crystallizes from dilute alcohol in orange-yellow prisms, united
in bushy aggregates, which melt at 97. It is converted into
metanitrotoluene when heated with a solution of nitrogen
trioxide. 2

Mctanitro-orthotoluidine (1 : 2 : 5) is obtained by the nitration
of acetorthotoluide and decomposition of the products with the
calculated quantity of alcoholic potash. It is readily soluble in
alcohol, but only very slightly in boiling water, from which it
crystallizes in small, citron-yellow needles, melting at 127 128.
On heating with an alcoholic solution of nitrogen trioxide,
metanitrotoluene is obtained, while when the amido-group is
replaced by bromine, orthobromometanitrotoluene is formed,
and can be converted into orthobromotoluene by means of the
diazo-reaction.

Paranitro-ortJwtoluidine (1:2:4). When the phthalyl-
toluide obtained by heating orthotoluidine with phthalic
anhydride is nitrated, two mononitro-compounds are formed,
one of which occurs only in small quantities and on decomposi-
tion with ammonia yields the orthonitro-orthotoluidine just
described, while the other gives paranitro-orthotoluidine, which
melts at 109, and may be converted into paranitrotoluene by
means of the diazo-reaction (Stadel). It is also formed when
orthotoluidine is dissolved in 10 parts of sulphuric acid and the
well-cooled solution treated with the calculated quantity of
nitric acid, mixed with twice its weight of sulphuric acid. The

1 Cunerth, Ann. Chcm. Pharm. clxxii. 223 ; Bernthsen, Ber. Dcutsch. Chcm.
Oes. xv. 3016 ; Stadel, Ann. Chcm. Pharm. ccxxv. 384.

2 Lcllmann and Wiirthner, ibid, ccxxviii. 239.
8 Beilttein and Kuhlberg, ibid, clviii. 345.



70 AKOMATIC COMPOUNDS.



corresponding nitracet-toluide is obtained in a similar manner
by dissolving acetorthotoluide in 20 parts of sulphuric acid ; if,
however, only 4 parts be taken, the acetyl-compound of meta-
nitro-orthotoluidine is also formed. 1

a-Orthonitrometatohiidine (1 : 3 : 2) is prepared by the nitra-
tion of acetmetatoluide and decomposition of the product with
alcoholic potash. It crystallizes in fine, saffron-yellow needles
melting at 132 134. On heating with an alcoholic solution
of nitrogen trioxide, it is converted into orthonitrotoluene
(Beilstein and Kuhlberg).

/3-Orthonitrometatoluidine (1:5:2) was obtained by Limpricht
from the corresponding dinitrotoluene (p. 71). It is slightly,
soluble in cold, more readily in hot water, and readily in alcohol ;
crystallizes in reddish yellow needles, and may be converted into
orthonitrotoluene by means of the diazo-reaction. 2

Orthonitroparatoluidine (1:4:2) was obtained by the partial
reduction of ordinary dinitrotoluene. 3 This compound alone is
formed when the reduction is effected with ammonium sulphide
in the cold; if, however, the mixture be warmed, paranitro-
orthotohu'dine is also formed. 4 Orthonitroparatoluidine is best
prepared by dissolving 100 grams, of paratoluidine in 2,000
grams, of concentrated sulphuric acid, and gradually adding a
mixture of 75 grams, of concentrated nitric acid with 300 grams.
of sulphuric acid to the solution cooled below 0. After standing
for some time, the liquid is poured into ice-water. 5 It crystal-
lizes from hot water in broad, yellow, monoclinic needles
(Panebianco), melting at 77'5, and may be converted into
orthonitrotoluene by means of the diazo-reaction.

Metanitroparatoluidine (1:4:3) was obtained by Beilstein
and Kuhlberg from acetnitroparatoluide ; the latter is best
prepared by dissolving acetparatoluide in 4 parts of sulphuric
acid, and adding the calculated amount of nitric acid mixed with
2 parts of sulphuric acid to the well-cooled solution. If the
amount of sulphuric acid be increased, the acetyl-compound of
Orthonitroparatoluidine is also formed, while metanitroparatolui-
dine can be obtained by the direct nitration of paratoluidine
if less sulphuric acid be used (Nolting and Collin).

1 Nolting and Collin, Ber. Deutsch. Chem. Oes. xvii. 261.

2 Ibid, xviii. 1401.

3 Bcilstein and Kuhlberg, Ann. Chcm. Pharm. civ. 14.

4 Limpricht, Bcr. Deutsch. Chem. Gcs. xviii. 1400 ; Graeff, Ann. Chcm. Pharm.
ccxxix. 340.

8 Nolting nnd Collin, loc. c.it.



DINITROTOLUIDINES. 71

It is readily soluble in alcohol, but only slightly in boiling
water, and crystallizes in red needles or prisms, melting at
116 . 1 On heating with a solution of ethyl nitrite, metanitro-
toluene is formed.

Metanitroparamethyltoluidine, C 6 H 3 (NO 2 )(CH 3 )NH(CH 3 ) ) is
obtained by heating nitrotoluidine with methyl iodide and
wood-spirit ; it crystallizes from alcohol in red needles, and from
benzene in tablets melting at 84 85.

Metanitropara-ethyltoluidine, C 6 H 3 (NO 2 )(CH 3 )NH(C 2 H 5 ), forms
large, red needles melting at 58 59 (Gattermann).



DINITROTOLUIDINES, C 6 H 2 (CH 3 )(NO 2 ) 2 NH 2 .

2052. a-Dinitro-orthotoluidine (1:3:5:2) is formed when
dinitro-orthocresyl ethyl ether is heated with alcoholic ammonia.
It is scarcely soluble in boiling alcohol, slightly in toluene, and
crystallizes in prisms or tablets which exhibit "a blue iridescence
and melt at 208 . 2

ft-Dinitrotoluidine is obtained by heating /3-trinitrotoluene
with alcoholic ammonia ; it crystallizes from glacial acetic acid
in short, golden-yellow needles, melting at 94.

y-Dinitrotoluidine is formed, even in the cold, by the action of
alcoholic ammonia on 7- trinitrotoluene ; it is almost insolublein the
ordinary solvents with the exception of hot acetone and glacial
acetic acid, and forms small, hard, golden-yellow crystals melting
at 192 193.

Adjacent Dinitroparatoluidine (1:3:5:4) is formed when
acetparatoluide is brought into concentrated nitric acid and the
product treated with alcoholic potash ; 3 it may also be obtained
by the action of alcoholic potash on dinitroparacresyl ethyl
ether. 4 It is slightly soluble in alcohol, and crystallizes from
carbon disulphide in yellow needles, melting at 168 . 5 Chromic
acid oxidizes it to chrysanisic acid, C 6 H 2 (CO 2 H)(NO 2 ) 2 NH 2 .

Symmetric Dinitroparatoluidine (1:2:6:4) is obtained by
the reduction of a-trinitro toluene with ammonium sulphide ; it

1 Gattermann, Ber. Dtutsch. Chem. Ges. xviii. 1482
- Stadel, ibid. xiv. 900.

a Beilstein and Kuhlberg, Ann. CJicm. Pharm. clviii. 341 ; Kelbe, Ber. Deutsch.
Chem Ges. viii. 877.
4 Stadel, loc. cit. Hiilmer, Ann. CJicm. Pharm. ccxxii. 74.



AROMATIC COMPOUNDS.



crystallizes from acetic acid in yellow, hair-like needles, melting

at 166'5 168. It does not yield chrysanisic acid on oxidation,

but a brown powder which is probably an azo-compound. 1

Thiotoluidine, (CH 3 .C 6 H 3 .NH 2 ) 2 S, is formed when paratolu-
idine is heated with sulphur and litharge to 140. It crystallizes
from alcohol in lustrous, odourless plates melting at 103, and is
a di-acid base. Its salts crystallize well, but are decomposed by
a large quantity of water. When the solution is heated with
ferric chloride or any other oxidizing agent, it first becomes
yellow, passing into brownish red, and then to dull red, a dark
flocculent precipitate being finally formed. 2



DIAMIDOTOLUENES, or TOLYLENEDIAMINES,

C 6 H 3 (CH 3 )(NH 2 ) 2 .

2053 a-Diamidotoluene,or ordinary Afetatoluyknediamine (1:2:4)
was discovered by Hofmann in the high boiling portions of crude
aniline oil, 3 and was then obtained by him as a product of the
reduction of ordinary dinitrotoluene with iron and acetic acid.
It is best prepared by the reduction of dinitrotoluene with tin
and hydrochloric acid. 4 It crystallizes from hot water in long
needles, melts at 99, and boils at about 280. Its aqueous
solution becomes dark-coloured in the air.

a-Diamidotolucne monohydrochloride, C 7 H 10 N 2 .HC1, is obtained
by dissolving the base in the calculated amount of hydrochloric
acid, and is left as a radiating crystalline mass when the
solution is evaporated. 5

a-Diamidotoluene dihydrochloride, C 7 H 10 N 2 (C1H) 2 , crystallizes
from warm hydrochloric acid in needles.

a-Diamidotoluene sv.lphate, C 7 H 10 N 2 .SO 4 H 2 + 2H 2 O, crystal-
lizes from water in long prisms, with a vitreous lustre, and is
precipitated in crystals by the addition of alcohol to its aqueous
solution.

p-Dia.midotolitsne, or Orthotoluylenediamine (1 : 3 : 4) is formed
by the reduction of metanitroparatoluidine with tin and hydro-

1 Reilstein, Bvr. DeutscJi. Chcm. Ges. xiii 243

* Merz and Weith, ibid. iv. 393.

3 Jahresb. Chtm. 1861, 512 ; Hell and Schoop, Ber. Deutosh. Chan. Oat. xii.

* Beilstein. An* m, Pharm. cxxx. 242.
5 Bernthsen, Ber. Deut*ch. CTiem. Ges. xi. 1 75<*



DIAMIDOTOLUENES. 73



chloric acid. It forms brilliant white scales, which are tolerably
stable when dry ; its aqueous solution, on the contrary, rapidly
becomes coloured black in the air. It melts at 88'5, and
boils at 265.

When a crystal is thrown into water it takes up a rapid
rotatory motion in dissolving, as do the other diamines (Pt. III.
p. 268).

^-Diamidotoluene hydrochloride, C 7 H 10 N 2 (C1H) 2 , crystallizes in
long, very soluble needles.

^-Diamidotoluene sulphate, 2(C 7 H 10 N 2 .S0 4 H 2 ) -f 3H 2 O, is more
readily soluble in water than the a-compound, and is precipitated
by alcohol in brilliant white scales, with a nacreous lustre. 1

Methyl - (3 - diamidotoluene, or Metamidoparamethyltoluidine,
C 6 H 3 (CH 3 ) (NH 2 ) NH (CH 3 ), is prepared in a similar manner
to the following compound, and crystallizes in four-sided tablets,
melting at 43 44.

Ethyl- ^-diamidotoluene, C 6 H 3 (CH 3 )(NH 2 )NH(C 2 H 5 ), is ob-
tained by the reduction of metanitropara-ethyltoluidine, and
crystallizes from sulphuretted hydrogen water in large, colourless
tablets, which melt at 54 55, and soon become dark-coloured
in the air. The peculiar rotatory motion assumed by the
diamines when dissolving in water was first observed with this
compound. A crystal which is not too heavy acquires such a
rapid motion that it appears to have a completely closed path.
A trace of fat on the water causes cessation of the motion
(Gattermann).

^-Diamidotoluene, or Paratoluylenediamine (1 : 3 : 5) was ob-
tained by Beilstein and Kuhlberg from metanitro-orthotoluidine ;
it is also formed when ortho-amido-azotoluene or metamido-
azotoluene is reduced with tin and hydrochloric acid. 2 It is
readily soluble in water, crystallizes from hot benzene in aggre-
gates of tablets, melts at 64, and boils at 273 274. On
oxidation with manganese dioxide and sulphuric acid, it yields
toluquinone.

y- Diamidotoluene hydrochloride, C 7 H 10 N 2 (HC1) 2 , crystallizes
from hot hydrochloric acid in small plates with a nacreous
lustre.

^-Diamidotoluene sulphate, C 7 H 10 N 2 .S0 4 H 2 , is slightly soluble
in cold, more readily in hot water, and is precipitated from this
solution by alcohol as a white powder.

1 Beilstein and Kuhlberg, Ann. Clum, Pharm. rlviii. 351.
1 Nietzki, Bcr. Dcutsch. Clwm. Gcs. X. 832, 1158.



74 AROMATIC COMPOUNDS.

As already mentioned, solutions of its salts to which a little
orthotoluidine has been added are coloured a deep green by
ferric chloride. Nietzki at first attributed the colouration to
paratoluylene-diamine alone, but he afterwards found that the
colour was only produced in samples prepared from ortho-amido-
azotoluene, which had not been completely freed from ortho-
toluidine ; the pure compound only gives the reaction after the
addition of the latter base.

S-Diamidotoluene (1:2: 3) is formed by the reduction of /3-
orthonitro-orthotoluidine. It forms red crystals, which are
readily taken up by the usual solvents, smell like acetamide,
melt at 61 62 and boil at 255 . 1



DIAZO-DERIVATIVES OF TOLUENE.

2 54. Only the derivatives of paratoluidine have hitherto
been prepared pure ; they are obtained by the methods used in
the preparation of the corresponding benzene derivatives. 2

The diazo-compounds of the two other toluidines have only
been obtained as intermediate products in the preparation of
derivatives ; many examples of this kind have already been
given.

Diazotoluene nitrate, CH 3 .C 6 H 4 N=NO.NO 2 , crystallizes in
white needles.

Diazotoluene sulphate, CH 3 .C 6 H 4 N=N.O.SO 2 .OH, forms lus-
trous needles or prisms.

Diazo-amidotoluene, CH 3 .C 6 H 4 N N.NH.C 6 H 4 .CH 3 , is pre-
pared by passing nitrogen trioxide into a solution of paratolu-
idine in a mixture of alcohol and ether. 3 It crystallizes in.
yellow or reddish yellow needles or prisms, and gives a platini-
chloride (C 14 H 16 N 3 ) 2 PtCl 6 , which forms yellow tablets.

Diazobenzcne-amidotoluene, C 6 H 5 N 2 .NH.C 6 H 4 .CH 3 , was ob-
tained by Griess as a product of the action of diazobenzene
nitrate on paratoluidine, 4 as well as of that of diazotoluene nitrate
on aniline. 5 It crystallizes in narrow, yellow plates. The
formation of the same compound by two different reactions

1 Lellmann and Wurthner, Ann. Chein. Pharm. ccxxviii. 243.
1 Griess, Jahresb. C/icm. 1866, 458.

3 Griess, Ann. CJicm. Pharm. cxxi. 277

4 Ibid, cxxxvii. 60.

5 Her. Deutsch. Cliem. Ges. vii. 1619.



AZOTOLUENES. 75



which should yield isomeric substances, is analogous to the case
of diazobromobenzene-arnidobenzene, which has been already
discussed.



HYDRAZINE-DERIVATIVES OF TOLUENE.

2055 Paratolylhydrazine, CH 3 .C 6 H 4 .NH=NH 2 , is prepared
from paratoluidine just as is phenylhydrazine from aniline.
It crystallizes from ethereal solution in rhombic tablets, melts
at 61, boils with slight decomposition between 240 244, and
is slightly soluble in water, but readily in alcohol. 1

Diparatolylhydrazine, (CH 3 .C 6 H 4 ) 2 N NH 2 , is formed by the
action of zinc-dust and acetic acid on diparatolylnitrosamine ;
it crystallizes from benzene in colourless plates melting at 171
172, and is a weak monacid base. Mercuric oxide converts it
into diparatolylamine without the formation of a tetrazone-com-
pourid (Pt. III. p 33). 2



AZO-DERIVATIVES OF TOLUENE.

2056 Azotoluenes, CH 3 .C 6 H 4 N=NC 6 H 4 .CH 3 , are formed by
reduction of the nitrotoluenes or oxidation of the toluidines, and
are converted into hydrazotoluenes, C 7 H 7 .NH NH.C 7 H 7 , by
further reduction.

Ortho-azotoluene is obtained by the action of zinc-dust and
alcoholic potash, or sodium amalgam and alcohol on orthonitro-
toluene, 3 as well as by the oxidation of orthotoluidine with



Online LibraryHenry E. (Henry Enfield) RoscoeA treatise on chemistry (Volume 3) → online text (page 7 of 50)