Org. Synth. 1950, 30, 106
DOI: 10.15227/orgsyn.030.0106
VINYL LAURATE AND OTHER VINYL ESTERS
[Lauric acid, vinyl ester]
Submitted by Daniel Swern and E. F. Jordan, Jr.
1.
Checked by William S. Johnson and Leland J. Chinn.
1. Procedure
In a 500-ml. round-bottomed three-necked flask provided with a thermometer, a reflux condenser, and a gas inlet tube through which a stream of nitrogen is passed (Note 1) are placed 206 g. (2.4 moles) of freshly distilled vinyl acetate (Note 2) and 80 g. (0.4 mole) of lauric acid (Note 3). The lauric acid is dissolved by warming, and 1.6 g. of mercuric acetate is added. The mixture is shaken by hand for about 30 minutes, and 0.15 ml. of 100% sulfuric acid is added dropwise (Note 4). The solution is heated under reflux for 3 hours, then 0.83 g. of sodium acetate trihydrate is added to neutralize the sulfuric acid. The excess vinyl acetate is recovered by distillation at atmospheric pressure (vapor temperature about 70–80°) until the pot temperature reaches 125° (Note 5). The distillation is completed at 10 mm. or lower (Note 5), and, after the collection of a small quantity of low-boiling material, fairly pure vinyl laurate (Note 6) is obtained as a colorless liquid, b.p. 142–143°/10 mm. (138–139°/8 mm.; 124–126°/3 mm.). The yield is 50–57 g. (55–63%). Redistillation (Note 7) yields 48–53 g. (53–59%) of pure vinyl laurate, b.p. 142–142.5°/10 mm. (120–120.5°/2 mm.); n25D 1.4387 (Note 8) and (Note 9).
2. Notes
1.
All operations should be conducted in a
nitrogen atmosphere to minimize the formation of polymer.
2.
An
Eastman Kodak Company practical grade of vinyl acetate is satisfactory. It was distilled immediately before use through a
48 by ¾ in. column packed with 3/32-in. single-turn Pyrex glass helices. The checkers employed material obtained from the Niacet Chemicals Division, Niagara Falls, New York, distilled once through a
12-in. Vigreux column, b.p.
73°/746 mm.3.
Lauric acid, m.p. 44°, was prepared from the commercial acid obtained from Armour and Company, Chicago, Illinois. The acid was recrystallized twice from
acetone at −40°
(10 ml. of acetone per gram of acid) and distilled under reduced pressure through a well-insulated, electrically heated
30 by 1 in. column packed with ¼-in. Berl saddles. Pure
lauric acid has a boiling point of
167–168°/8 mm. and
n45D 1.4316. The
Eastman Kodak Company grade of lauric acid melting at
43–44° is satisfactory.
4.
The
100% sulfuric acid is prepared by cautiously adding
7.3 g. of fuming sulfuric acid containing
30% sulfur trioxide to
10 g. of 95% sulfuric acid.
5.
An electrically heated
18 by ½ in. Vigreux column was employed.
6.
The
vinyl laurate, which has an acid number of about 2, usually contains a small quantity of
mercury at this stage, from which it can be separated by decantation.
7.
Sufficient
sodium bicarbonate is added to the pot charge to neutralize the free acid present
(Note 6).
8.
Additional properties of
vinyl laurate are
n35D 1.4345 and
d304 0.8639. If the
iodine number is determined by the Wijs method, a 200% excess of
iodine chloride solution and a 1-hour reaction period should be employed in order to obtain values which are 97–99% of the theoretical value.
9.
Vinyl caproate, caprylate, pelargonate, caprate, myristate, palmitate, stearate, 10-hendecenoate (undecylenate) and oleate can be prepared in a similar manner, except that in the preparation of the
palmitate and
stearate the fatty acids are added to a solution of
mercuric acetate and
sulfuric acid in
vinyl acetate.
Vinyl stearate is not redistilled, but the once-distilled product is recrystallized from
acetone at 0° (
3 ml. of acetone per gram of
vinyl stearate). The amount of
mercuric acetate employed was 2%, and the amount of
100% sulfuric acid was 0.3–0.4%, of the weight of the
stearic acid. Average yields and properties of these vinyl esters are given in the table.
|
|
Vinyl Ester
|
Yield, %
|
Boiling Point
|
n30D
|
d304
|
|
°C.
|
mm.
|
|
|
Caproate
|
40
|
98–99
|
100
|
1.4159
|
0.8837
|
|
Caprylate
|
55
|
134–135
|
100
|
1.4256
|
0.8719
|
|
Pelargonate
|
55
|
133–133.5
|
50
|
1.4291
|
0.8689
|
|
Caprate
|
45
|
148
|
50
|
1.4320
|
0.8670
|
|
Myristate
|
60
|
147–148
|
4.8
|
1.4407
|
0.8617
|
|
Palmitate (m.p. 26.7–27.1°)
|
35
|
168–169
|
4.5
|
1.4438
|
0.8602
|
|
Stearate (m.p. 35–36°)
|
30
|
187–188
|
4.3
|
1.4423 (at 40°)
|
0.8517 (at 40°)
|
|
10-Hendecenoate
|
70
|
124–124.5
|
10
|
1.4442
|
0.8799
|
|
Oleate
|
60
|
178
|
2.8
|
1.4533
|
0.8691
|
|
The acids used for preparing the vinyl esters tabulated were Eastman Kodak Company pure grade except for the following, which were obtained from the companies indicated and purified by fractionation through an
efficient fractionating column:
caproic acid, b.p. 96°/8 mm., Carbide and Carbon Chemicals Corporation, New York;
caprylic acid, b.p.
124–125°/8 mm.,
capric acid, b.p. 145–146°/8 mm., Armour and Company, Chicago, Illinois;
pelargonic acid, b.p. 176°/64 mm., Emery Industries, Cincinnati, Ohio;
10-hendecenoic (undecylenic) acid, b.p. 177–180°/25 mm., Baker Castor Oil Company, New York.
Oleic acid was prepared from olive-oil fatty acids by low-temperature crystallization and distillation.
2
3. Discussion
The procedure described is substantially that of Toussaint and MacDowell,
3 with minor modifications.
4 Vinyl esters of long-chain aliphatic acids have also been prepared by the reaction of
acetylene with the appropriate acids,
5,6,7,8 but this reaction is not so convenient for small-scale laboratory preparations.
The interchange reaction of
vinyl acetate with
lauric acid in the presence of
mercuric sulfate has been studied,
9 and
vinyl laurate has been obtained also from
lauryl chloride and
acetaldehyde in the presence of
pyridine.
10
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
Vinyl caproate, caprylate, pelargonate, caprate, myristate, palmitate, stearate, 10-hendecenoate (undecylenate) and oleate
acetaldehyde (75-07-0)
sulfuric acid (7664-93-9)
acetylene (74-86-2)
sulfur trioxide (7446-11-9)
sodium bicarbonate (144-55-8)
nitrogen (7727-37-9)
mercuric acetate (1600-27-7)
mercury (7439-97-6)
iodine (7553-56-2)
acetone (67-64-1)
pyridine (110-86-1)
Caproic acid (142-62-1)
mercuric sulfate (7783-35-9)
oleic acid (112-80-1)
iodine chloride (7790-99-0)
caprylic acid (124-07-2)
stearic acid (57-11-4)
lauric acid (143-07-7)
Pelargonic acid (112-05-0)
vinyl acetate (108-05-4)
sodium acetate trihydrate (6131-90-4)
stearate
lauryl chloride (112-52-7)
10-hendecenoic acid (112-38-9)
Vinyl laurate,
Lauric acid, vinyl ester (2146-71-6)
palmitate
Vinyl stearate (111-63-7)
capric acid (334-48-5)
Vinyl Caproate
vinyl caprylate
vinyl pelargonate
vinyl caprate
vinyl myristate
vinyl palmitate
vinyl 10-hendecenoate
vinyl oleate
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