A
2-l. three-necked flask is fitted with a
dropping funnel, a stopcock, and a
long condenser. The end of the condenser is connected with the following assembly: a
safety trap, consisting of an empty gas-washing bottle; a
second wash bottle containing 100 cc. of dilute sulfuric acid (1 volume of concentrated sulfuric acid to 2 volumes of water); a
tower, about 30 cm. high, containing calcium chloride; an
empty 2-l. flask which acts as a trap; a
2-l. flask containing
80.5 g. (3.5 gram atoms) of clean sodium dissolved in 1.5 l. of absolute alcohol; an
empty 1-l. flask and a
1-l. flask containing 500 cc. of a saturated solution of lead acetate (Note
1). The exit tube from this last flask leads to a suction pump.
After
556 g. (2 moles) of methyl isothiourea sulfate (p. 411) is placed in the three-necked flask, a very slow current of air is drawn through the apparatus by means of the
suction pump while
800 cc. of cold 5 N sodium hydroxide is added to the
methyl isothiourea sulfate through the dropping funnel. The mixture is warmed very slowly to generate the
methyl mercaptan (Note
2). As the reaction nears completion (after about two hours), the mixture is heated strongly for about thirty minutes (Note
3).
The solution of
sodium methyl sulfide in absolute
alcohol is transferred to a
3-l. three-necked flask, which is placed on a
steam bath and fitted with a
dropping funnel, a
reflux condenser, and a
mechanical stirrer. The solution is heated until the alcohol begins to boil. Heating is then discontinued and
302 g. (3.75 moles) of ethylene chlorohydrin (Note
4) is added dropwise with efficient stirring over a period of about two hours (Note
5). The reaction mixture is concentrated by distilling as much of the alcohol as possible on the steam bath. The mixture is then allowed to cool and the
sodium chloride removed by filtration. The flask is rinsed and the
sodium chloride washed with
three 100-cc. portions of 95 per cent alcohol. The combined filtrate and washings are concentrated on the steam bath under reduced pressure until no further distillate passes over. The residue is then transferred to a
modified Claisen flask and fractionally distilled under reduced pressure. The yield is
238–265 g. (
74–82 per cent of the theoretical amount based on the
sodium used) of a product boiling at
68–70°/20 mm. (Note
6).