Weygand/Hilgetag Preparative Organic Chemistry

Benzene series
p-Fluorop-Chlorop-Biomo-
3,4-Dichloro-
2,5-Dibromo-
Replacement of hydrogen by sulfur groups 629
M.p.
O
35-36 a
53.5*
75.4
18-19
71 b
4-Fluoro-3-methyl- Oil
4-Chloro-2-methyl- 52-53 c
a From benzene or ether. b After 1
c After lOminutes' heating at 50°.
hours' heating.
Naphthalene
series
4-Chloro-
7-Chloro-
4-Bromo-
7-Bromo-
M.p.
(°)
92- 93
124-126
81- 83
142-143
Pollak and his co-workers reported the preparation of hydroxybenzene- 218
and hydroxynaphthalene-sulfonyl chlorides. 219
For the preparation of aminoarenesulfonyl chlorides it is advisable to
protect the amino group by acylation, 220 " 222 but this is unnecessary when
2-aminopyridine is converted into 6-amino-2,5-pyridinedisulfonyl chloride
(79% yield) by hot chlorosulfuric acid. 223
Sulfonyl chlorides of aromatic carboxylic acids can be obtained from chlorides
of the latter by treatment with sulfonating agents that do not produce water
during the reaction. 224
m-Chlorosulfonylbenzoic add: 224 Sulfur trioxide is passed into benzoyl chloride (100 g) at
110° until a weight increase of 71.3 g has been achieved. The mixture is kept at 130° for
a further 2 h, taken up in chloroform, and washed with ice-water. After removal of the chloroform
by distillation and recrystallization of the residue from toluene the product has m.p. 133°.
To avoid side reactions and multiple chlorosulfonation it is often advisable
to use an inert solvent such as chloroform or carbon tetrachloride. Side reactions
can also be produced by the water formed, and this can be bound by an
excess of chlorosulfuric acid or, better, oleum, phosphorus pentaoxide, or
thionyl chloride.
The chlorosulfonyl group can, finally, be introduced into aromatic compounds
by using the chloride of disulfuric acid 225 or sulfuryl chloride, 226 1he
latter in the presence of condensing agents such as aluminum chloride.
3. Direct introduction of the sulfone and sulfoxide group
Direct introduction of a sulfone group RSO2 into aromatic compounds in
place of a hydrogen atom occurs during sulfonation by sulfuric acid, but
218 J. Pollak and E. Gebauer-Fulnegg, Monatsh. Chem., 47, 537 (1927).
219 J. Pollak, E. Gebauer-Fulnegg, and E. Blumenstock-Halward, Monatsh. Chem., 49,
187 (1928); J. Pollak and E. Blumenstock-Halward, Monatsh. Chem., 49, 203 (1928).
220 Cf. G. F. Lisk, Ind. Eng. Chem., 42, 1751 (1950).
221 Ger. Pat. 573,193; Chem. Abstr., 27, 2966 (1933).
222 R. N. Johnson and S. Smiles, /. Chem. Soc, 123, 2384 (1923).
223 E. J. Cragoe, J.A.Nicholson, and J. M. Sprague, /. Med. Pharm. Chem., 4, 369
(1961).
224 French Pat. 872,771; Chem. Zentralbl., 1942, II, 2219.
225 W. Steinkopf and K. Buchheim, Ber. Deut. Chem. Ges., 54, 2963 (1921).
226 H. C. Brown, Ind. Eng. Chem., 36, 788 (1944).