Process for preparing 4-hydroxyacetophenone oxime with mother liquor recycle

• US 4,994,613 A
• Filed: 01/29/1990
• Issued: 02/19/1991
• Est. Priority Date: 02/16/1983
• Status: Expired due to Term

• Current Assignee: BASF Corporation (BASF SE)
• Original Assignee: Hoechst Celanese Corporation (Sanofi )
• Inventors: Fruchey, Olan S.
• Primary Examiner(s): Raymond, Richard L.
• Application Number:
  US07/470,410
• Time in Patent Office: 386 Days
• Field of Search: 564/259, 564/223, 564/300, 564/383
• US Class Current: 564/259
• CPC Class Codes: C07C 249/08 by reaction of hydroxylamines with carbonyl compounds
• CPC Class Codes: C07C 251/48 with the carbon atom of at least one of the oxyimino groups bound to a carbon atom of a six-membered aromatic ring

Abstract

A novel process is disclosed for the preparation of 4-hydroxyacetopheone oxime by reaction of 4-hydroxyacetophenone with a hydroxylamine in caustic wherein the mother liquor obtained after crystallization of the oxime together with the wash water is recycled back and reused. This invention illustrates the criticality of maintaining the reactants in certain critical mol ratios in order to obtain 4-hydroxyacetopheone oxime of acceptable color.

Claims

1. In the process for the production of 4-hydroxyacetophenone oxime by the conversion of 4-hydroxyacetophenone utilizing hydroxylamine, the improvement which comprises forming said 4-hydroxyacetophenone oxime and crystallizing the same from a mother liquor;

washing said crystallized 4-acetophenone oxime;

combining said wash water with said mother liquor; and

recycling at least a portion of said combined liquor back to the reaction vessel for oxime production while maintaining the following mol ratio of reactants;

caustic;

4-hydroxyacetophenone 1-4% molar excess

caustic;

hydroxylamine 1-4% molar deficiency.

2. The process of claim 1 wherein said source of hydroxylamine is hydroxylammonium sulfate and said base is ammonium hydroxide.

3. The process of claim 2 wherein the total amount of mother liquor recycled is about 50 wt. %

4. The process of claim 2 wherein a waste stream is recovered containing about 15 wt. % of ammonium sulfate.