In a
2-l. flask, provided with a
mechanical stirrer and cooled by an ice-salt mixture, are placed
300 cc. of ether and
186 g. (2 moles) of a 33 per cent aqueous methylamine solution. When the stirred mixture has cooled to 5°,
217 g. (2 moles) of ethyl chloroformate (Note
1) is added without allowing the temperature to rise above 5°. When almost half of the chloroformate has been added a cold solution of
80 g. (2 moles) of pure sodium hydroxide in 120 cc. of water is added gradually along with the rest of the chloroformate at such a rate that the last portions of the two solutions are added simultaneously. Constant mechanical stirring throughout the addition is essential (Note
2). After standing for fifteen minutes, the
ether layer is separated and the aqueous solution is extracted with
100 cc. of ether. The combined
ether layers are rapidly dried by shaking for a short time with about
8 g. of potassium carbonate in two portions. The
ether is then distilled and the residue distilled under reduced pressure, the distillate being collected at
55–60°/12 mm. The yield of colorless oil is
182–185 g. (
88–90 per cent of the theoretical amount).