Org. Synth. 1949, 29, 92
Submitted by C. R. Noller
Checked by C. F. H. Allen and F. W. Spangler.
A 3-l. Pyrex flask (Note 1)
is fitted with an efficient mechanical stirrer
, a dropping funnel
, a thermometer
, and an upright tube (Note 2)
to act as an air condenser
and to carry the trimethylene oxide
vapors through a spiral condenser
. In the flask are placed 1344 g. (24 moles) of potassium hydroxide
and 120 ml. of water. The contents are heated to about 140° with stirring (Note 3)
. The upper part of the flask should be kept sufficiently hot so that the potassium hydroxide
mush which is thrown up on the sides does not solidify. The spiral condenser is then packed with an ice-salt mixture, and 1092 g. (8 moles) of γ-chloropropyl acetate (p. 203) (Note 4)
is slowly run into the flask by means of the dropping funnel so that the distillate comes over at the rate of about 1 drop a second. The time required for the addition is 1.5–3 hours. After all the ester has been added, the mixture is stirred, with continued heating at 140–150°, until the distillate amounts to 250–400 g., depending on how efficiently the air condenser has separated the trimethylene oxide
from higher-boiling substances. About 100 g. of potassium hydroxide pellets
is added to the crude distillate, which is then distilled through a 25-cm. fractionating column
packed with ¼-in. Berl Saddles. By careful distillation the trimethylene oxide
can be obtained in a single fractionation, the portion boiling at 45–50°
being collected. The higher-boiling residue still contains some trimethylene oxide
, but consists mostly of water, allyl alcohol
, and unchanged γ-chloropropyl acetate
. The yield is 195–205 g.
). Redistillation over freshly fused potassium hydroxide
gives a product boiling at 47–48°
A half-gallon jacketed iron autoclave
may be employed.
A plain 90-cm. 10-mm. tube or a 30-cm. Vigreux column
is equally satisfactory.
An electric heating mantle is advisable. The reaction is exothermic, and if it appears to become too vigorous the current is temporarily discontinued.
The submitter states that a yield of 20–25%
may be obtained when trimethylene chlorohydrin
is substituted for the acetate, with 2 moles of potassium hydroxide
and 10 ml. of water per mole of chlorohydrin.
This procedure is an improvement upon that of Reboul,1
and of Derick and Bissell.2
Reboul, as also did Ipatow,3
used trimethylene chlorohydrin
, but the yield is higher from the acetate.
Chemical Abstracts Nomenclature (Collective Index Number);
Allyl alcohol (107-18-6)
potassium hydroxide pellets (1310-58-3)
Trimethylene chlorohydrin (627-30-5)
γ-Chloropropyl acetate (628-09-1)
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