Process for producing Diels-Alder adducts while inhibiting the formation of polymeric by-products
AssigneeChemische Werke Huls Aktiengesellschaft
InventorsWilhelm Donike, Helmut Ulrich, Heinz Thiemer, Josefa Pieper
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Abstract
A process for preventing the formation of polymeric by-products during the production of Diels-Alder adducts is improved by the addition of NO or of a compound splitting off NO in situ, as a polymerization inhibitor. This process is especially effective for preventing the formation of polymeric by-products in the manufacture of 5-vinylnorbornene-2. In a tubular reactor, when observing narrow temperature and pressure ranges, a high selectivity is obtained in the production of this adduct.
Claims9
In a process for preparing 5-vinylnorbornene-2 by the Diels-Alder reaction of 1,3-butadiene with cyclopentadiene, dicyclopentadiene or a mixture thereof, at a temperature of 120.degree.-250.degree. C., with exclusion of oxygen, and in the presence of an effective polymerization inhibiting amount of a polymerization inhibitor, and recovering the 5-vinylnorbornene-2 thereby prepared,
- the improvement wherein said polymerization inhibitor is nitric oxide (NO), a nitric oxide precursor capable of liberating NO in situ, or a mixture thereof.
Dependencies are inferred from the claim text.