C07C 51/54
Preparation of carboxylic acid anhydrides
Official title: Preparation of carboxylic acid anhydrides (by oxidation C07C51/16)
C07C51/54 (Preparation of carboxylic acid anhydrides) appears on 583 US grants and 158 published applications in this corpus.
Search patents in C07C- Granted patents
- 583
- Published applications
- 158
- Assignees
- 220
- Inventors
- 963
- Latest grant
- 26 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 36 | 0 |
| 1977 | 17 | 0 |
| 1978 | 17 | 0 |
| 1979 | 8 | 0 |
| 1980 | 26 | 0 |
| 1981 | 18 | 0 |
| 1982 | 23 | 0 |
| 1983 | 13 | 0 |
| 1984 | 21 | 0 |
| 1985 | 32 | 0 |
| 1986 | 29 | 0 |
| 1987 | 21 | 0 |
| 1988 | 14 | 0 |
| 1989 | 13 | 0 |
| 1990 | 22 | 0 |
| 1991 | 17 | 0 |
| 1992 | 13 | 0 |
| 1993 | 21 | 0 |
| 1994 | 15 | 0 |
| 1995 | 8 | 0 |
| 1996 | 11 | 0 |
| 1997 | 9 | 0 |
| 1998 | 11 | 0 |
| 1999 | 9 | 0 |
| 2000 | 13 | 0 |
| 2001 | 5 | 1 |
| 2002 | 3 | 7 |
| 2003 | 14 | 11 |
| 2004 | 4 | 6 |
| 2005 | 6 | 10 |
| 2006 | 8 | 3 |
| 2007 | 7 | 8 |
| 2008 | 3 | 6 |
| 2009 | 6 | 10 |
| 2010 | 7 | 7 |
| 2011 | 5 | 6 |
| 2012 | 4 | 4 |
| 2013 | 8 | 3 |
| 2014 | 6 | 10 |
| 2015 | 8 | 5 |
| 2016 | 5 | 4 |
| 2017 | 3 | 10 |
| 2018 | 7 | 5 |
| 2019 | 6 | 5 |
| 2020 | 4 | 9 |
| 2021 | 10 | 6 |
| 2022 | 2 | 6 |
| 2023 | 2 | 5 |
| 2024 | 6 | 3 |
| 2025 | 6 | 4 |
| 2026 | 1 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Integrated process for generating acid anhydrides26 May 2026US 12,637,405 B2Cleantech Building Materials PLC
- Process for distillative purification of unsaturated carboxylic anhydrides25 Nov 2025US 12,479,789 B2Evonik Operations GmbH
- Method for producing fatty alcohol esters of hydroxycarboxylic acids22 Jul 2025US 12,365,645 B2KetoLipix Therapeutics GmbH
- Process for generating acid anhydrides15 Jul 2025US 12,358,860 B2Cleantech Building Materials PLC
- Synthesis and purification of CBDA20 May 2025US 12,304,885 B2The Regents of the University of Colorado, a body corporate
- Integrated process for generating acid anhydrides10 Sep 2026US 2026/0265171 A1Cleantech Building Materials PLC
- Integrated process for generating acid anhydrides18 Jun 2026US 2026/0167596 A1Cleantech Building Materials PLC
- Recovery of maleic anhydride19 Mar 2026US 2026/0078101 A1Huntsman Petrochemical Corporation
- Process for the preparation of bio-based olefins from primary alcohol5 Mar 2026US 2026/0062361 A1BASF SE
- Catalytic carboxycarbonylation of alkenes to form anhydrides4 Dec 2025US 2025/0368598 A1Eastman Chemical Company
Most cited
By later US patents
- Formation, purification and recovery of phthalic anhydride253US 4,215,051 AStandard Oil Company (Indiana) · 1980
- Process for the preparation of ethanol from methanol, carbon monoxide _and hydrogen170US 4,497,967 AThe Halcon SD Group, Inc. · 1985
- Integrated process for producing carbonylation acetic acid, acetic anhydride, or coproduction of each from a methyl acetate by-product stream131US 7,115,772 B2Celanese International Corporation · 2006
- Ashless dispersants formed from substituted acylating agents and their production and use115US 5,241,003 AEthyl Petroleum Additives, Inc. · 1993
- Ashless dispersants formed from substituted acylating agents and their production and use82US 5,137,980 AEthyl Petroleum Additives, Inc. · 1992