Organic Syntheses, CV 3, 613
Submitted by W. S. Bishop
Checked by C. F. H. Allen and J. VanAllan.
1. Procedure
A.
ω-Carbomethoxypelargonyl chloride. A mixture of
216 g. (1 mole) of methyl hydrogen sebacate (Note
1) and
147 g. (1.24 moles) of thionyl chloride in a
2-l. round-bottomed flask attached by a standard ground-glass joint to an upright condenser is refluxed on a
steam bath for 5 hours. The condenser is then replaced by a still head having a modified side arm, and the unused
thionyl chloride is removed. The residual
ω-carbomethoxypelargonyl chloride is suitable for the next step. If a purer product is desired it is distilled under reduced pressure. The yield of ester chloride boiling at
158–160°/10 mm. is
194–201 g. (
83–86%).
B.
Methyl sebacamate. Two and one-half liters of concentrated aqueous
ammonia (about 28%) in a
4-l. beaker or enameled pot (Note
2) is stirred vigorously with an off-center stirrer and chilled to 8° in a cooling bath. The crude chloride from part A is added slowly from a
dropping funnel to the solution, which is kept below 8° throughout the addition. A vigorous reaction takes place, and
methyl sebacamate precipitates immediately. After the addition has been completed, the product is filtered by suction and washed with 200 ml. of cold water. After 3 days' drying in a
vacuum desiccator, the
methyl sebacamate weighs
200–204 g. (
93–95%) and melts at
72–74° (Note
3).
2. Notes
2. A variety of enameled-steel pots known as bain-marie is available from the American Specialty Company, Rochester, New York.
3. The yield is no higher with the distilled chloride.
3. Discussion
These compounds have been described in the literature.
2,3
This preparation is referenced from:
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