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US 5,847,157 AGranted
Method of producing (+) 2-azabicyclo{2.2.1}hept-5-en-3-one
AssigneeDegussa AG
InventorsFrank Romanowski, Kurt Vroman, Rudolf Vanheertum
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Abstract
The present invention relates to a simplified method of producing .+-.2-azabicyclo2.2.1!hept-5-en-3-one from cyclopentadiene and sulfocyanides by reacting cyclopentadiene with sulfonylcyanides without the use of organic solvents.
Claims7
A method of producing a 2-azabicyclo{2.2.1}hept-5-en-3-one product by reacting 1,3-cyclopentadiene with a substituted sulfonylcyanide in the presence of water, comprising:
- a) reacting a sulfinate of the general formula
- RSO.sub.2 X (I)
- in which R signifies ethyl, propyl, benzyl, 4-methylbenzyl, 4-nitrobenzyl, or 2-nitrobenzyl, X signifies an alkali cation Na or K, or H, in water as a single solvent with chlorine cyanide to produce a sulfonylcyanide of general formula
- RSO.sub.2 CN (II),
- b) subsequently reacting the sulfonylcyanide without intermediary isolation, with 1,3-cyclopentadiene,
- c) filtering off a sulfinate precipitate of a byproduct, produced in the reaction, to produce a filtrate,
- d) adjusting pH of the filtrate with an aqueous solution of alkali hydroxide to a pH value between 7 and 8.5, and
- e) isolating the product from the filtrate by extraction.
5 more elements
Dependencies are inferred from the claim text.