Org. Synth. 1957, 37, 65
DOI: 10.15227/orgsyn.037.0065
Submitted by J. Meinwald and N. J. Hudak1.
Checked by J. D. Roberts, C. M. Sharts, and W. G. Woods.
1. Procedure
A 1-l. steel bomb is charged with 200 g. (1.5 moles) of dicyclopentadiene (Note 1). The bomb is flushed with ethylene (Note 2) and then filled while shaking to an initial pressure of 800–900 p.s.i. at 25°. Shaking is continued as the bomb is slowly heated (Note 3) to 190–200° and maintained at this temperature for 7 hours (Note 4). At the end of this period, the reaction vessel is cooled and vented, and the crude product is transferred to a simple distillation apparatus (Note 5). A fraction boiling between 93° and 100° is collected, yield 162–202 g. (57–71%, based on dicyclopentadiene) (Note 6). The norbornylene may be redistilled with negligible losses to give a final product, b.p. 94–97°/740 mm., m.p. 44–44.5° (sealed capillary).
2. Notes
1. The dicyclopentadiene used by the submitters was supplied by the Enjay Company. No preliminary purification is required. Technical (85%) dicyclopentadiene has been found by the checkers to give 54–56% yields of norbornylene without preliminary purification.
2. C.P. grade ethylene was obtained from the Matheson Company.
3. To avoid complications due to the exothermic nature of this reaction,2 a rate of heating of about 50° per hour was adopted (cf. (Note 6)).
4. Near 180°, the maximum pressure (about 2350 p.s.i.) is developed.
5. In spite of the low melting point of norbornylene, the product has a remarkable tendency to crystallize. Care should therefore be taken to prevent premature solidification of the distillate. A short-path, air-cooled assembly using rather wide-diameter tubing is convenient for this purpose.
6. The submitters report the same yields using a 3-l. bomb and 3.68 moles of dicyclopentadiene. Larger-scale preparations may necessitate special control procedures.
3. Discussion
The procedure described above is essentially that of Thomas.2 Norbornylene has also been prepared by the addition of ethylene to monomeric cyclopentadiene3 (p. 238), by dehydration of β-norborneol with phosphorus pentoxide,4 and by dehydrohalogenation of norbornyl chloride or bromide using quinoline.4,5
This preparation is referenced from:

References and Notes
  1. Cornell University, Ithaca, New York.
  2. Thomas, Ind. Eng. Chem., 36, 310 (1944); Thomas and Universal Oil Products, U. S. pat. 2,340,908 [C. A., 38, 4273 (1944)].
  3. Joshel and Butz, J. Am. Chem. Soc., 63, 3350 (1941).
  4. Komppa and Beckmann, Ann., 512, 175 (1934).
  5. Alder and Rickert, Ann., 543, 10 (1940).

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)


norbornyl chloride or bromide

ethylene (9002-88-4)

Quinoline (91-22-5)


dicyclopentadiene (77-73-6)

Norbornylene (498-66-8)


phosphorus pentoxide (1314-56-3)