Henry E. (Henry Enfield) Roscoe.

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acid :*

C 6 H 6 . CH 2 .O.NH 3 C1 + SHI = C 6 H 5 .CH 2 I + NH 4 C1 + H 2 + 1 2 .



SUBSTITUTION PRODUCTS OF BENZYL
ALCOHOL AND ITS DERIVATIVES.

2068 Substitution-products are not formed by the direct
action of chlorine, bromine, or nitric acid on benzyl alcohol,
since all these reagents produce oxidation. Its ethers, hoAv-
ever, can undergo direct substitution, and if an atom of
hydrogen in one of them be replaced, para-compounds are
formed, from which the corresponding alcohols may readily

i Beilstein and Kuhlberg, Ann. Chem. Pharm. cxlvii. 341.
Dumas and Dema^ay, Compt. Rend. Ixxxiii. 688.

3 Meyer and Ccresole, Ber. Deutsch. Chem. Ges. xv. 3071

4 Janny, ibid. xvi. 170.



SUBSTITUTION PRODUCTS OF BENZYL ALCOHOL. 99

be obtained. Thus, parachlorobenzyl alcohol, C 6 H 4 CLCH 2 .OH, is
prepared by boiling its chloride or bromide with water :

C 6 H 4 Cl.CH 2 Br + H 2 O = C 6 H 4 C1.CH 2 OH + HBr.

The haloid ethers can also be converted into the acetate by boil-
ing with alcohol and potassium acetate, and this saponified by
heating with ammonia :

C 6 H 4 C1.CH 2 .0. C 2 H 3 + NH 3 = C 6 H 4 C1.CH 2 .OH + C 2 H 3 O.NH 2 .

The higher chlorinated benzyl chlorides have been converted
into their alcohols by means of this reaction.

Paranitrobenzyl alcohol can readily be prepared by nitrating
benzyl acetate or oxalate and heating the product with am-
monia.

Chlorine substitution-products of benzyl chloride can be
obtained, as already mentioned, by treating it with chlorine in
the cold or in presence of iodine, as well as by allowing chlorine
to act upon the vapour of boiling, chlorinated toluene. Accord-
ing to Beilstein and Kuhlberg, the latter is tlje better method,
and is now generally adopted.

The bromine substitution-products are prepared in a similar
manner; the use of this method has shown that substitution
does not readily take place in the methyl group when bromine
is allowed to act on boiling orthobromotoluene.

Paranitrotoluene is converted by bromine at high temperatures
into paranitrobenzyl bromide ; paranitrobenzyl chloride and
metanitrobenzyl bromide can also be readily obtained, but not
the ortho-compound. If orthonitrotoluene be heated with
bromine, no orthonitrobenzyl bromide is found, but the product,
according to Wachendorff, consists of dibromorthonitrotoluerie,
C G H 2 Br 2 (N0 2 )CH 3 , which is not attacked by potassium acetate
or silver acetate even at 160 . 1 It possesses the exceptional
property of dissolving in aqueous alkalis and being reprecipitated
by mineral acids, and Greiff was therefore induced to examine ib
more carefully. He found that it is not dibromonitrotoluene, but
the isomeric dibromortho-amidobenzoic acid,C 6 H 2 Br 2 (NH 2 )C0 2 H.
Since the isomerides of orthonitrotoluene behave quite differently
towards bromine, it follows that the ortho-position facilitates a
mutual exchange between the oxygen of the nitroxyl and the

1 Ann. Chcm. Pharm. clxxxr. 259.

H 2



100 AROMATIC COMPOUNDS.

hydrogen of the methyl. How this interniolecular change takes
place has not yet been explained, but it seems probable that
orthonitrobenzyl bromide is first formed and is then con-
verted by the nitroxyl group into ortho-amidobenzoic acid,
just as benzyl chloride is oxidized to benzoic acid by nitric
acid.

2069 Parachlorolenzyl alcohol, C 6 H 4 C1.CH 2 .OH, is formed by
boiling the corresponding bromide or chloride with water, 1 or by
heating parachlorobenzyl acetate to 100 with aqueous ammonia. 2
It is readily soluble in alcohol, scarcely in cold, but somewhat
more readily in warm water, from which it crystallizes in long
needles melting at 70'5 (Jackson and Field). Oxidizing agents
convert it into parachlorobeuzoic acid.

Melting-point.

Dichlorobenzyl alcohol, 3 C 6 H 3 C1,.CH 2 OH, needles 77
Trichlorobenzyl alcohol, 4 C 6 H 2 C1 3 '.CH 2 OH, crystals
Tetrachlorobenzyl alcohol, 5 C 6 HC1 4 .CH 2 OH,
Pentachlorobenzylalcohol, 6 C 6 Cl 5 .CH 2 .OH, short needles 193

Parachlorobenzyl ethyl ether, C 6 H 4 C1.CH 2 .O.C 2 H 5 , is formed by
heating parachlorobenzyl chloride 7 or parachlorobenzyl acetate 8
with alcoholic potash ; it is a liquid which boils at 218 , 9 and
is split up by chlorine in the cold into ethyl chloride and
parachlorobenzaldehy d e.

Phenylchlorocarlyldhyl ether, or Benzylethoxyl chloride, C 6 H 5 .
CHC1.O.C 2 H B , is prepared by boiling benzylidene chloride,
C 6 H 6 .CHC1 2 , for a long time with alcoholic ammonia. It is a
liquid which boils at 210 212 and is converted into ethyl
metanitrobenzoate, C 6 H 4 (N0 2 )CO.OC 2 H 5 , by nitric acid. 10

Parachlorobenzyl chloride, C 6 H 4 C1.CH 2 C1, is obtained together
with a little of the ortho-compound, by the chlorination of
benzyl chloride in presence of iodine, and by the action of
chlorine on boiling monochlorotoluene, as a liquid which boils
at 213 214 . 11 It is prepared pure from parachlorotoluene ; 12
it crystallizes from alcohol in lustrous needles or prisms which

M * Jackson and Field, Ber. Deutsch. Chcm. Ges. xi. 905 ; Amor. Chcm. Journ

11- OO.

Beilstein and Kuhlberg, Ann. Chcm. Pharm. cxlvii. 344.

Ibid. 350 Ibid. clii. 241. s Ibid. 245. Ibid. 246

Naquet, ibid. Suppl. [2] 250. Neuhof, ibid, cxlvii. 345

Smteius, ibid. clxi. 335.

Hiibner and Bente, Bcr. Deutsch. Chem. Ges. vi. 805.

Neuhof, Ann. Chcm. Pharm. cxlvi. 320.

Jackson and Field, Ber. Deutsch. Chcm. Ges. xi. 904



PARABROMOBENZYL ALCOHOL. 101

melt at 29, readily sublime, and possess an aromatic vapour
which attacks the mucous membrane very violently.

Melting- Boiling-

Dichloro- \ point. point.

benzyl- V C 6 H 3 C1 2 .CH 2 C1, liquid . . 241

chloride, 1 j
Trichloro- \

benzyl- VC 6 H 2 C1 3 .CH 2 C1, . . 273

chloride, 2 J
Tetrachloro- S

benzyl- V C 6 HC1 4 .CH 2 C1, ,. . . 296

chloride, 3 J
Pentachloro- \

benzyl- V C C1 5 .CH 2 C1, fine needles 103 325 327
chloride, 4 j



Parachlorobenzyl bromide, C 6 H 4 Cl.CH 2 Br, resembles the
chloride very closely ; it melts at 48-5 . 5

Parachlorobenzyl acetate, C 6 H 4 C1.CH 2 .O.C 2 H 3 O, is obtained
by boiling the chloride with potassium acetate and absolute
alcohol ; it is a liquid which boils at 240 and- has an aromatic
odour. 6

Parabromobenzyl alcohol, C 6 H 4 Br.CH 2 .OH, is formed when
the bromide is boiled with water for several days ; it crystallizes
from a hot solution in flat, elastic, pearly needles which have an
aromatic odour, melt at 69, and only volatilize slowly with steam. 7

Parabromobenzyl bromide, C 6 H 4 Br.CH 2 Br. This compound is
prepared by passing bromine vapour into a boiling mixture of
parabromotoluene and orthobromotoluene, which is obtained by
the direct bromination of toluene. After the calculated quantity
has been added, the liquid is allowed to cool, a portion of the
bromide crystallizing out in large, rhombic prisms. The mother-
liquor is then distilled with steam in which the ortho- is more
readily volatile than the para-compound. The latter can also
readily be obtained in long, thick, transparent prisms by allowing
bromine to act upon the mixture of bromotoluenes in the sun-
light. 8 Parabromobenzyl bromide crystallizes from alcohol in
needles which melt at 61 and are volatile with steam ; its vapour



Beilstein and Kuhlberg, Ann. Cham. Pharm. cxlvi. 146, 326.

Ibid. cl. 290. * Ibid. 299. * Ibid. 302.

Field and Jackson, loc. cit.

Neuhof, Ann. Ch^m. Pharm. cxlvii. 345.

Jackson and Lowry, Bcr. DcAitsch. Chf,m. Ges. x. 1209.

Schramm, ibid. xvii. 2922 ; xviii. 350.



102 AROMATIC COMPOUNDS.

has a pleasant, aromatic odour, but attacks the eyes, nose, and
throat very violently. 1

Pardbromolenzyl acetate, C 6 H 4 Br.CH 2 .O.C 2 H 3 O, is a liquid
which has a pleasant smell resembling that of acetic ether, and
decomposes on distillation. 2

Metdbromobenzyl bromide, C 6 H 4 Br.CH 2 Br, is obtained in a
similar manner to the para-compound ; the yield is, however, very
poor. It crystallizes in plates or needles which melt at 41, and
its vapour attacks the mucous membrane violently, but has
a somewhat different smell from that of the para-compound.
It only volatilizes slowly in a current of steam, but with remark-
able rapidity in ether and tolerably readily in alcohol. It is not
attacked by chromic acid solution, but the corresponding alcohol,
which has not been further investigated, is oxidized by it to
metabromobenzoic acid. 3

Orthobromobenzyl alcohol, C 6 H 4 Br.CH 2 .OH, crystallizes from
hot water in flat needles, which melt at 80, and readily volatilize
with steam. 4

Orthobromobenzyl bromide, C 6 H 4 Br.CH 2 Br, is only formed with
difficulty, and has not been obtained pure, since it decomposes on
distillation. It is an oily liquid, which does not solidify at 15,
volatilizes with steam, possesses an aromatic odour, and rapidly
attacks the mucous membrane ; a drop placed on the tongue
causes severe pain. 5 Sodium acts upon its ethereal solution with
formation of various products, among them being anthracene :

CH



Para-iodobenzyl alcohol, C 6 H 4 I.CH 2 .OH, crystallizes from carbon
disulphide in scales and from boiling water in long needles,
which have an aromatic odour and melt at 71'7. 6

Para-iodobenzyl bromide, C 6 H 4 I.CH 2 Br, is formed by the action
of bromine vapour on heated para-iodotoluene, and crystallizes
from alcohol in flat, white needles, which melt at 787, possess
an aromatic odour, and attack the mucous membrane less
violently than the bromobenzyl bromides. Boiling water con-
verts it into the alcohol. 7

1 Schramm, Bcr. Ddttsch. Chem. Gcs. viii. 1672 ; ix. 931.

2 Jackson and Lowry, ibid. x. 1209.

1 Jackson and White, Amer. Chem. Journ. ii. 315. 4 Jackson, Bcr. Deutsch.
Chem. Ges. viii. 932. & Jackson, Bcr. Deutsch. Chem. Ges. ix. 932.

Jackson and Mabery, ibid. xi. 56 ; Amcr. Chem. Journ. ii. 251.
7 Jackson and Mabery, loc. cit.



PARANITROBENZYL ALCOHOL. 103



2070 Paranitrobenzyl alcohol, C 6 H 4 (NO 2 )CH 2 .OH, is prepared
by heating its acetate or oxalate with ammonia to 100 , 1 and by
the action of caustic soda on paranitrobenzaldehyde. 2 It crystal-
lizes from boiling water in fine, lustrous, colourless needles, which
become coloured in the air and melt at 93. On oxidation it
yields paranitrobenzoic acid.

Paranitrobenzyl chloride, C 6 H 4 (NO2).CH 2 C1, is obtained, to-
gether with the ortho- and meta-compounds, by the action of
concentrated nitric acid on benzyl chloride, 3 the chloride being
gradually added to the acid which has been previously cooled to
15. 4 It is also formed by treating paranitrotoluene with
chlorine at 185 190 . 5 It crystallizes from boiling alcohol in
fine, white needles, or small, nacreous plates, which melt
at 76.

An alkaline solution of pyrogallol reduces it to paranitro-
toluene. 6

Paranitrobenzyl bromide, C 6 H 4 (NO 2 )CH 2 Br, is formed when
paranitrotoluene is heated to 120 130 with bromine ; the
reaction takes place at 70 80 in the presence of ferrous
bromide, which acts as a bromine carrier. 7 - On the gradual
evaporation of its solution in a mixture of ether and alcohol, it
crystallizes in thin tablets, which melt at 99 100. It destroys
the skin, producing a burning pain, and the vapour given off by
its hot alcoholic solution attacks the mucous membrane most
violently (Wachendorff).

Paranitrobenzyl iodide, C 6 H 4 (NO 2 )CH 2 I, is obtained by heat-
ing the chloride with potassium iodide and alcohol ; it crystallizes
in four-sided tablets, melting at 127, and its vapour produces
a flow of tears. 8

Paranitrobenzyl nitrate, C 6 H 4 (N0 2 )CH 2 NO 3 . Beilstein and
Kuhlberg prepared this compound by the action of concentrated
nitric acid on the alcohol, and believed that it was dinitrobenzyl
alcohol. Stadel found, however, that it loses nitric acid when
heated with water to 100, and that it yields paranitrobenzoic
acid on oxidation, 9 and Orth prepared it by heating the chloride

Beilstein and Kuhlberg, Ann. Chcm. Pharm. cxlvii. 343.
Easier, Ber. Dcutech. Che-m. Ges. xvi. 2715.

Beilstein and Geitner, Ann. Chcm. Pharm. cxxxix. 327 ; Grimaux, ibid. cxlv.
146 ; Abelli, Gaz. Chim. Ital. xiii. 97.

' Strakosch, Bcr. Dcutsch. Chcm. Ges. vi. 10f>6.
Wacheudorfr, Ann. Chcm. Pharm. clxxxv. 271.
Pellizzari, Bcr. Dcutsch. Chcm. Ges. xviii. Kef. 150.
Seheufeln, Ann. Chcm. Pharm. ccxxxi. 177.
Kumpf, Bcr. Dcutsch. Chcm. Ges. xvii. 1074. 9 Ibid. xiv. 903.



104 AROMATIC COMPOUNDS.

with alcohol and silver nitrate. 1 It crystallizes from hot water
in fine, white needles, and from alcohol in long, flat needles,
melting at 71.

Paranitrolenzyl acetate, C 6 H 4 (NO 2 )CH 2 .C 2 H 3 O 2 , is obtained
hy dissolving benzyl acetate in well-cooled concentrated nitric
acid (Beilstein and Kuhlberg) or by heating the chloride with
potassium acetate and alcohol (Grimaux). It crystallizes from
hot alcohol in long, pale yellow needles, melting at 78.

Paranitrobenzyl oxalate, (C 6 H 4 (NO 2 )CH 2 ) 2 C 2 4 , was obtained
by Beilstein and Kuhlberg by dissolving benzyl oxalate in
concentrated nitric acid; on heating with aqueous ammonia
it is converted into the alcohol.

2071 Metanitrobenzyl alcohol, C 6 H 4 (N0 2 )CH 2 . OH, was prepared
by Grimaux, together with metanitrobenzoic acid, by the action
of alcoholic potash on metanitrobenzaldehyde as a thick, oily
liquid, which decomposes on heating, but boils at 178 180
under a pressure of 3 mm. 2

Metanitrobenzyl chloride, C 6 H 4 (NO 2 )CH 2 C1, is formed by the
action of phosphorus pentachloride on the alcohol ; it crystallizes
from hot petroleum ether in long, light yellow needles, which
melt at 45 47, and produces painful irritation and burning on
the skin. 3

Orthonitrolenzyl alcohol, C 6 H 4 (NO 2 )CH 2 .OH. When ortho-
nitrotoluene is given to a dog, it appears in the urine as ortho-
nitrobenzoic acid, and as the urea salt of uronitrotoluic acid t
2Cj 3 H 15 N0 9 .CO(NH 2 ) 2 + 5H 2 O, crystallizing in long needles,
which are very readily soluble in water, slightly in cold alcohol,
and insoluble in ether. On boiling this with baryta water and
decomposing the barium salt formed with sulphuric acid, nro-
nitrotoluic acid, C 13 H 15 N0 9 , is obtained as a crystalline mass
resembling asbestos, which is extremely soluble in water and
alcohol and has a strongly acid reaction. On boiling with dilute
sulphuric acid it decomposes into a syrupy acid and orthonitro-
benzyl alcohol ; 4 this compound can also be prepared by the
action of caustic soda on orthonitrobenzaldehyde. 5 It is slightly
soluble in water, readily in alcohol and ether, and crystallizes in
long, fine needles, which melt at 74, and can be sublimed, but
detonate when rapidly heated.

Kumpf, Bcr. Dcutsch. Chem. Gcs. xv. 1136. Zeitschr. Chem. 1867, 562.

3 Gabnel and Borgmann, Ber. Deutsch. Chem. Ges. xvi. 2064

4 Jaffe, Hoppe-Seyler's Zeitschr. ii. 47.

5 Friedlander and Henriques, Ber. Deutsch. Chem. Gcs. xiv. 2801



SULPHUR COMPOUNDS OF BENZYL. 105



Orthonitrobenzyl chloride, CgH^NO.^CH.jCl, is formed, as
already mentioned, together with its isomerides, by the nitration
of benzyl chloride, and was first isolated from the product by
Kumpf. 1 It is also obtained by the action of phosphorus penta-
chloride on the alcohol. 2 It crystallizes from petroleum ether in
large rhombohedra melting at 48 49.

Orthonitrobenzyl iodide, C 6 H 4 (N0 2 )CH 2 I, is prepared by heat-
ing the chloride with potassium iodide and alcohol; it forms
rhombohedral plates melting at 75, and its vapour causes a flow
of tears.

Orthamidobenzyl alcohol, (^^(NH^CHg.OH, is obtained by
the action of hydrochloric acid and zinc-dust on Orthonitrobenzyl
alcohol in alcoholic solution. It crystallizes from benzene in
white needles, which melt at 82, become coloured brown in the
light or in the air, and Jiave a faint smell resembling that of
aniline.

It combines with acids forming soluble, crystallizable salts. 3



SULPHUR COMPOUNDS OF BENZYL.

2072 Benzyl hydrosulphide, or Benzyl mercapfan, C 6 H 5 .CH 2 .SH.
Marcker obtained this compound by heating benzyl chloride or
benzyl bromide with an alcoholic solution of potassium hydro-
sulphide. 4 Otto prepared it by the action of benzyl chloride on
potassium thiosulphate, 5 and Bottinger by fusing thiobenzalde-
hycle, C 6 H 5 .CSH, with caustic potash, benzyl disulphide and a
little benzoic acid being simultaneously formed. 6

It is a colourless, powerfully refractive liquid which has an
unpleasant smell of leeks, boils at 195, and has a sp. gr. of
1'058 at 20; its vapour produces a flow of tears. It gradually
oxidizes in the air, more rapidly in the presence of ammonia to
benzyl disulphide ; an ethereal solution of bromine produces the
same effect.

Mercury benzyl mercaptide, (C 6 H 5 .CH 2 S) 2 Hg, is formed by
heating the hydrosulphide with mercuric oxide ; it crystallizes
from alcohol in long, silky needles. Mercuric chloride, in

Friedlander and Henriques, Ber. Deutsch. Chem. Oes. xvii. 1073.
Gabriel and Borgmann, Ber. Deutsch. Chem. Gcs. xvi. 2064.
Friedlander and Henriques, ibid. xv. 2109.

Ann. Chem. Pharm. cxxxvi. 75. * Zeitschr. Chem. [2] vi. 23.

Ber. Dcutsch. Chem. Ocs. xii. 1055.



106 AROMATIC COMPOUNDS.

alcoholic solution, gives with the mercaptan a white precipitate
of 6 H 5 .CH 2 .S.HgCl.

Lead benzyl mercaptide, (C 6 H 5 .CH 2 S) 2 Pb, is obtained in small
yellow plates by mixing hot, alcoholic solutions of lead acetate
and benzyl mercaptan.

Parachlorobenzyl hydrosulphide, C 6 H 4 C1.CH 2 .SH, is formed
when parachlorobenzyl chloride is boiled with an alcoholic solu-
tion of potassium hydrosulphide. According to Beilstein, it is
obtained in lustrous crystals, melting at 84 85 , 1 while accord-
ing to Jackson and White, it is an oily liquid which possesses a
most repulsive and penetrating odour, and solidifies on cooling
in crystals which melt at 19 20. 2

Paranitrobenzyl hydrosulphide, C 6 H 4 (N0 2 )CH 2 .SH, crystallizes
from alcohol in small, colourless, lustrous plates, melting at 140 . 3

Benzyl ethyl sulphide, C 6 H 5 .CH 2 .S.C 2 H 5 , is prepared by the
action of ethyl iodide on a solution of sodium in benzyl hydro-
sulphide, and is a transparent liquid, which boils at 214 216 , 4
and possesses a penetrating odour resembling that of ordinary
mercaptan.

Orthobenzyl thioformate, (C 6 H 5 .CH 2 .S) 3 CH, is formed when
an aqueous solution of sodium benzyl mercaptide is heated
with chloroform; it separates from hot alcohol in colourless
crystals, melting at 98. When heated with fuming nitric
acid to 250, it is decomposed into benzyl mercaptan and
formic acid. 5

Benzyl sulphide, (C 6 H 5 .CH 2 ) 2 S. Miircker obtained this com-
pound by heating benzyl chloride with an alcoholic solution of
potassium sulphide. It crystallizes from hot alcohol in large,
dazzling white plates, and from ether or chloroform in large,
thick, rhombic tablets, 6 melting at 49. On distillation it yields
stilbene, C 14 H 12 , and sulphuretted hydrogen; dibenzyl, C 14 H 14 ,

C 6 H 5 .C X
tolallyl sulphide, or tolan sulphide 1 1 >S and thionessal or

C 6 H 5 .C/
tetraphenyl thiophene C 4 S.(C 6 H 5 ) 4 are simultaneously formed. 7

Methyl iodide and benzyl sulphide react even in the cold,
more rapidly on warming, with formation of lenzyldimethyl-
sulphine iodide, C 6 H 5 .CH 2 (CH 3 ) 2 SI, and trimethylsulphine iodide,

1 Beilstein, Ann. Chem. Pharm. cxvi. 347 ; cxlvit. 346. 2 Amer. Chem.

Journ n. 167. Strakosch, Ber. Dcutsch. Chem. Ges. v. 598.

Marcker, Ann. Chem. Pharm. cxl. 88. Dennstedt, Ber. Dcutsch.

Chem, Ges xi. 2265. Forst, Ann. Chem. Pharm. clxxviii. 671.

Marcher, loc. ctt. Baumann and Klatt, Bcr. Dcutsch. Chem. Gcs. xxiv. 3307.



SULPHUR COMPOUNDS OF BENZYL. 107

(CH 3 ) 3 SI. The first stage of the reaction is represented by the
following equation :

2CH 3 I+ (C 6 H 5 .CH 2 ) 2 S = (CH 3 ) 2 S+ 2C H 5 .CH 2 I.

The methyl sulphide then combines with the iodides forming
the compounds mentioned. If the product be extracted with
water, shaken up with silver chloride and the nitrate then
fractionally precipitated with platinum chloride, benzyl dimethyl-
sulphine platinichloride, (C 6 H 5 .CH 2 (CH 3 ) 2 S) !l PtCl 6 , separates out
first ; it crystallizes from water in long, orange-red needles. 1

Cahours, 2 who has also investigated the action of methyl
iodide on benzyl sulphide, gives the following equation :

3CH 3 I + (C 6 H 5 .CH 2 ) 2 S = (CH 3 ) 3 SI + 2C 6 H 5 .CH 2 I.

Benzyl bromide and methyl sulphide, on the other hand, react
in the following way :

C G H 5 .CH 2 Br + 2(CH 3 ) 2 S = (CH 3 ) 3 SBr+C 6 H 5 .CH 2 .S.CH 3 .

If methyl alcohol be also present, benzyl methyl ether is
formed instead of benzyl methyl sulphide :

C 6 H 5 .CH 2 Br + (CH 3 ) a S + 2CH 3 .OH =
(CH 3 ) 3 SBr + C 6 H V CH 2 .O.CH 3 + H 2 O.

Benzyl oxysulphide, (C 6 H 5 .CH 2 ) 2 SO, is formed by the action of
concentrated nitric acid on the sulphide ; it crystallizes from
alcohol in small plates which have a satin lustre, melt at 133 , 3
and are converted into sulphuric acid and benzoic acid by
the further action of nitric acid (Marcker).

Benzyl disulphide, (C 6 H 5 .CH 2 ). ! S 2 , is best obtained by the
action of bromine in ethereal solution on benzyl mercaptan, and
is also formed when benzyl chloride is treated in alcoholic
solution with potassium disulphide ; it crystallizes from alcohol
in small, lustrous plates, melting at 66 67. Nascent hydrogen
reconverts it into benzyl mercaptan (Marcker). It is decomposed
on heating, yielding the same products as benzyl sulphide.

Benzyl dioxy sulphide, or Dibenzyl sulpkone, (C 6 H 5 .CH 2 ) 2 SO 2 , is
formed in small quantity in the preparation of potassium benzyl

1 Scholler, Bcr. Deutsch. Chem. Ges. vii. 1274.

- Compt. Rend. Ixxx. 1319.

3 Otto and Liiders, Bcr. Deutsch. Chem. Ges. xiii. 1284.



108 AROMATIC COMPOUNDS.

sulphonate. 1 It may readily be obtained, however, by oxidizing
benzyl oxysulphide with potassium permanganate and glacial
acetic acid (Otto and Liiders) ; it is insoluble in water, and
crystallizes from hot alcohol in flat needles, which melt at 150.

2073 Benzylsulphonic acid, C 6 H 5 .CH 2 .SO 2 .OH. Bohler pre-
pared this compound by boiling benzyl chloride for several
hours with a concentrated solution of normal potassium sulphite,
the potassium salt obtained being converted into the lead salt,
and this decomposed with sulphuretted hydrogen. 2 It is a
deliquescent crystalline mass, and is also formed by the oxidation
of benzyl disulphide with nitric acid, 3 When it is fused with
caustic potash, it yields benzoic acid (Yogt), together with some
benzene and a larger quantity of toluene. 4

Potassium lenzylsulphonate, C 6 H 5 .CH 2 .S0 3 K + H 2 O, crystal-
lizes from hot water in well-developed rhombic prisms.

Barium lenzylsulphonate, (C 6 H 5 .CH 2 .S0 3 ) 2 Ba + 2H 2 O, is
obtained by the addition of barium chloride to the solution of
the potassium salt ; it forms plates, which are only slightly
soluble in water.

Lead benzylsulphonate, (C (i H 5 .CH 2 .S0 3 ) 2 Pb. If the barium
salt be decomposed with dilute sulphuric acid, and the hot
nitrate saturated with lead hydroxide, the basic salt C 6 H 5 .CH 2 .
S0 3 .PbOH, is obtained as a lustrous, crystalline precipitate,
which is converted into the normal salt by carbon dioxide ; this
crystallizes from hot water in lustrous plates.

Potassium chlorobenzylsulphonate, C 6 H 4 C1.CH 2 .SO 3 K + H 2 O,
is prepared from chlorobenzyl chloride and potassium sulphite,
and crystallizes in needles; barium chloride added to the
potassium salt yields barium chlorobenzylsulphonate, (C 6 H 4 C1.
CH 2 .S0 3 ) 2 Ba + H 2 0, which forms colourless lustrous crystals.

When the potassium salt is fused with caustic potash, sali-
cylic acid and parahydroxybenzoic acid are formed (Vogt and
Henninger).

Benzylsulphonic chloride, C H 5 .CH 2 .S0 2 C1. Barbaglia endea-
voured to prepare this compound by the distillation of potassium
benzylsulphonate with phosphorus pentachloride, but only ob-
tained benzyl chloride, together with phosphorus oxychloride
and some thionyl chloride. 5 In order to prepare it, the potas-
sium salt is treated with an equal weight of phosphorus chloride



and Henninger, Ann. Chem. Pharm. clxv. 375. 2 Ibid. cliv. 50.

Barbagha, Ber. Deutsch. Chem. Gcs. v. 687.
4 Otto, ibid. xiii. 1288. 8 Ibid v 270



SELENIUM COMPOUNDS OF BENZYL. 103

and the mixture gently warmed until the reaction is complete.
The product is then washed with water and the residue crystal-
lized from ether. Benzenesulphonic chloride forms colourless
prisms, which melt at 92 and are decomposed when more
strongly heated into benzyl chloride and sulphur dioxide ; it is con-



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