SYMMETRICAL DIETHYL SULPHITE. 209
- Amyl Nitrite, C 5 HU.ONO, and Methyl Nitrite, CH 3 .ONO.
Amyl nitrite is easily formed by the action of nitrous acid on amyl alcohol.
Since neither amyl nitrite nor amyl alcohol are miscible with water, the prog-
ress of this esterification is not retarded by the presence of water.
To 50 g. of amyl alcohol and 300 g. of cold, 20% sulphuric acid
in a 750-c.c. flask add 60 g. of sodium nitrite in small portions
while shaking the flask continuously and cooling under the water
tap. Wait, before adding each fresh portion, until the reaction
from the previous addition is ended and the yellowish-red vapors
have disappeared from the flask. About 30 minutes is required
for this operation. After waiting an hour longer, separate the
layers in a separatory funnel, wash the oily layer twice by giving
it a rotary motion with water (but do not shake it, as an emulsion
then forms which will separate into layers only on long standing),
free the liquid from drops of water, and let it dry by standing
overnight with lumps of fused calcium chloride. Distil the ester
from a fractionating flask with a side-arm condenser. Boiling-
point, 97°. Yield, about 60 grams.
Methyl Nitrite.
Methyl alcohol and amyl nitrite interact readily with the formation of
methyl nitrite and amyl alcohol. Amyl nitrite is much used in organic
chemistry as a reagent in preparing nitroso and diazo compounds.
Mix amyl nitrite with about one-third its weight of methyl
alcohol. After a short time, or sooner on warming gently, methyl
nitrite (boiling-point, — 12°) begins to escape as a gas. By using
25 g. of amyl nitrite and 7 g. of methyl alcohol, several cylinders
full of gas may be obtained. When set on fire it burns with a pale
flame.
- Symmetrical Diethyl Sulphite, SO(OC 2 H 5 ) 2.
There are two isomeric substances of the composition (C 2 H 5 ) 2 SO 3 , both of
which are to be regarded as esters of sulphurous acid. One of them is pro-
duced by the action of thionyl chloride on ethyl alcohol, and upon being
saponified it yields sulphurous acid and alcohol; the other can be formed
from a sulphite and a halogen alkyl, or by the esterification of ethyl sulphonic
acid, C 2 H 5 SO 2 .OH. Since it is only possible for thionyl chloride to have
the structural formula O : SC1 2 , the ester formed from it must have the cor-
responding symmetrical structure
, CI. OC 2 H
O : S +2 HOCN 2 H 5 = 2 HC1 + O : S '
Cl \ OC 2 H 6
