1. An oil-sealed stirrer was found unsuitable because the pressure drop through the system was greater than the pressure drop across the oil-sealed stirrer. The Trubore stirrer and bearing were purchased from Ace Glass Inc., Vineland, New Jersey.

2. The potassium hydroxide was weighed as flakes, then ground rapidly with a mortar and pestle to roughly the consistency of granulated sugar, and added as soon as possible to the reaction flask to minimize moisture uptake. The flakes may be used directly without grinding, the only difference being that the mixture of potassium hydroxide, glycol, and Cellosolve should be heated for a slightly longer time before any dichlorobutene is added in order to allow as complete a dispersion as possible.

3. The butyl Cellosolve is added to control the foaming during the reaction.

4. The dichlorobutene used was Eastman Kodak Company technical grade. Distillation before use was not observed to increase the yields.

5. The rate of addition is very important. If the time of addition of 1 mole of dichlorobutene goes much beyond 1 hour, the yield will decrease noticeably.

6. This is apparently an optimum temperature. Lower temperatures lead to lower yields, while higher temperatures do not change the yield appreciably.

7. The calculations of yields are based on d⁻⁸⁰ = 0.8 extrapolated from data at higher temperature.²

8. The preparation also has been run on a 2-mole scale, using double the quantities specified in a 3-l. flask. The yields obtained were comparable to those obtained on the 1-mole scale.

9. The low-temperature column shown in Fig. 12 was 75 cm. long, made of 7-mm. glass tubing. The entire column was surrounded by an evacuated, silvered jacket. The column, for the lower 60 cm., was a tightly coiled spiral (3.8 cm. diameter). The remaining length was straight and was surrounded by a coolant cup in which liquid of any temperature could be placed to control the refluxing temperature. For the purpose, a calcium chloride-water-Dry Ice mixture was used to keep the temperature of the cup at approximately −5 to 0°. The vapor from the column was condensed and collected in a graduated cylinder immersed in an acetone-Dry Ice bath (Note 10). The major features of infrared spectra of the vapor from redistilled product are summarized in Table I (Note 11).

10. Warming the still pot with 60° water was necessary to distil all the volatile gases toward the end of the distillation.

11. The spectrum of the fractionated monovinylacetylene was comparable, in band peaks and intensities, with previously reported spectra. A previously reported band at 5.8 μ, however, was not found in any of the samples, suggesting that an impurity was present in the sample previously reported.