Neat (solventless) hydrogenation of 4-acetoxyacetophenone in the production of 4-acetoxystyrene and its polymers and hydrolysis products

• US 5,084,533 A
• Filed: 07/25/1990
• Issued: 01/28/1992
• Est. Priority Date: 07/19/1988
• Status: Expired due to Term

• Current Assignee: TriQuest LP (The Chemours Company)
• Original Assignee: Hoechst Celanese Corporation (Sanofi )
• Inventors: Shah, Bakulesh N., Keene, Donna L.
• Primary Examiner(s): Bleutge, John C.
• Assistant Examiner(s): SWEET, MARK D
• Application Number:
  US07/558,023
• Time in Patent Office: 552 Days
• Field of Search: 526/75, 525/371
• US Class Current: 526/75
• CPC Class Codes: C07C 49/825 all hydroxy groups bound to the ring
• CPC Class Codes: C07C 69/017 Esters of hydroxy compounds having the esterified hydroxy group bound to a carbon atom of a six-membered aromatic ring
• CPC Class Codes: C08F 112/22 Oxygen
• CPC Class Codes: C08F 12/22 Oxygen

Abstract

A process for the solventless (neat) hydrogenation of 4-acetoxyacetophenone to produce 4-acetoxyphenyl methylcarbinol. The reaction proceeds by heating at 54° C. to 120° C. with an excess of hydrogen in the presence of a Pd/C or activated nickel such as Raney Nickel catalyst in the absence of a solvent. The 4-acetoxyphenyl methylcarbinol may then be dehydrated to 4-acetoxystyrene. The later may be polymerized to poly(4-acetoxystyrene) and hydrolyzed to poly(4-hydroxystyrene).

Claims

1. A process for the production of 4-acetoxystyrene which comprises:

a) acylating phenol with acetic anhydride to produce 4-hydroxyacetophenone; and

b) acylating the 4-hydroxyacetophenone with acetic anhydride to form 4-acetoxyacetophenone; and

c) heating 4-acetoxyacetophenone at a temperature of from about 54°

C. to about 120°

C. in the presence of at least a stoichiometric amount of hydrogen, and a catalyst selected from the group consisting of Pd/C or activated nickel in the absence of a solvent, for a sufficient time to produce 4-acetoxyphenyl methylcarbinol; and

d) dehydrating the 4-acetoxyphenyl methylcarbinol to produce 4-acetoxystyrene.

2. The method of claim 1 wherein the catalyst is Pd/C.

3. The method of claim 1 wherein the catalyst is Raney Nickel.

4. The method of claim 1 wherein the reaction step (c) is conducted until substantial completion of hydrogenation.

5. The method of claim 1 wherein the reaction step (c) is conducted at a pressure of from about 14 psig to about 5,000 psig.