Method for preparing anthraquinones
AssigneeKorea Kumho Petrochemical Co., Ltd.
InventorsYoung J. Joo, Jin-Eok Kim, Jeong-Im Won, Kum-Ui Hwang
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Abstract
A method for preparing anthraquinones, by which 1,4-benzoquinone or 1,4-naphthoquinone and 1,3-butadienes are subjected to a 2+4! Diels-Alder reaction and subsequently to oxidative dehydrogenation by using dimethylsulfoxide as a dehydrogenating agent in a single pot in the presence of a Lewis acid or Broensted acid shows high selectivity and yield.
Claims5
A method for preparing anthraquinones unsubstituted or substituted with at least one C.sub.1 -C.sub.4 alkyl group through a 2+4! Diels-Alder reaction of 1,4-naphthoquinone or 1,4-benzoquinone with 1,3-butadienes unsubstituted or substituted with at least one C--C alkyl group and a dehydrogenation of 1,4,4a,9a-tetrahydroanthraquinones obtained from the 2+4! Diels-Alder reaction using a Lewis acid or Broensted acid as an oxidative catalyst for dehydrogenation, the method comprising the step of:
- carrying out simultaneously the 2+4! Diels-Alder reaction and the oxidative dehydrogenation in a single pot by using dimethylsulfoxide as a dehydrogenating agent and as a solvent for the 2+4! Diels-Alder reaction.
Dependencies are inferred from the claim text.