Process for the preparation of linear 1,3-diketones

US5344992A · kind A · utility

Assignee

• Ciba-Geigy · US

Inventors

• Rolf Drewes · Bad Bellingen, DE
• Hans-Helmut Friedrich · Herbstein, DE
• Hans Mehner · Lampertheim, DE
• Bernd Braun · Herbstein, DE
• Walter Wecht · Rimbach, DE

Key dates

• Filing date: May 11, 1993
• Grant date: Sep 6, 1994
• Expiry date: May 11, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C319/20
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

There is disclosed a process for the preparation of 1,3-diketones of formula I ##STR1## wherein R.sub.1 and R.sub.2 are each independently of the other C.sub.1 -C.sub.20 alkyl, phenyl or phenyl which is substituted by halogen, hydroxy, NO.sub.2, C.sub.1 -C.sub.4 alkyl and/or C.sub.1 -C.sub.4 alkoxy, C.sub.7 -C.sub.9 phenylalkyl or a radical of formula II EQU --A--X--R.sub.4 (II) PA0 wherein PA0 A is C.sub.1 -C.sub.12 alkylene, phenylene or phenylene which is substituted by halogen, hydroxy, NO.sub.2, C.sub.1 -C.sub.4 alkyl and/or C.sub.1 -C.sub.4 alkoxy, or is C.sub.1 -C.sub.12 alkylene which is substituted by hydroxy, halogen and/or alkoxy, PA0 X is oxygen or sulfur, and PA0 R.sub.4 is hydrogen, C.sub.1 -C.sub.18 alkyl, phenyl or phenyl which is substituted by halogen, hydroxy, PA0 C.sub.1 -C.sub.4 alkyl, NO.sub.2 and/or C.sub.1 -C.sub.4 alkoxy, or is C.sub.7 -C.sub.9 phenylalkyl, and PA0 R.sub.3 is hydrogen, C.sub.1 -C.sub.20 alkyl, phenyl or phenyl which is substituted by halogen, hydroxy, C.sub.1 -C.sub.4 alkyl, NO.sub.2 and/or C.sub.1 -C.sub.4 alkoxy, or is C.sub.7 -C.sub.9 phenylalkyl. The process comprises carrying out a Claisen condensation of a ketone of formula III ##STR2…