# US 4,398,035 A · Malonic acids and esters thereof

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- Number: US 4,398,035 A
- Document ID: US4398035A
- Status: Granted
- Kind: A
- Application number: 06/193,660
- Filed: 1980-10-03
- Granted: 1983-08-09
- Earliest claimed: 1979-12-19
- Assignees: The Upjohn Company
- Inventors: Jerry A. Walker
- Web page: https://patentgrep.com/patent/US4398035A

## CPC

- C07C 57/58: containing six-membered aromatic rings
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The invention concerns the novel compounds dialkyl 2-(3-fluoro-4-nitrophenyl)-2-methylmalonate IIIa and dialkyl 2-(3-fluoro-4-aminophenyl)-2-methylmalonate IVa useful as intermediates in an improved process for making 2-(2-fluoro-4-biphenylyl)propionic acid, known as flurbiprofen, having the formula ##STR1## and ester thereof. It has anti-inflammatory activity which is about 240 times that of aspirin and analgesic activity which is about 180 times that of aspirin in standard laboratory tests. However, despite this high activity, the toxicity (LD.sub.50) is only 1.2 to 2.4 times greater than that of aspirin in standard laboratory tests. Also within the invention is a novel method of making the above intermediates and analogs thereof useful to prepare corresponding biaryl compounds which have pharmaceutical uses.

## Claims

### Claim 1

A compound having the formula ##STR32## wherein R is selected from the group consisting of hydrogen, alkyl of from 1 to 6 carbon atoms, inclusive, and the two R's taken together are dialkyl methylene to form a cyclic diester.

### Claim 2 (depends on 1)

A compound according to claim 1 wherein the two R's are ethyl so that the specific embodiment is diethyl 2-(4-amino-3-fluorophenyl)-2-methyl malonate.

### Claim 3

A compound having the formula ##STR33## wherein R is selected from the group consisting of hydrogen, alkyl of from 1 to 6 carbon atoms, inclusive, and the two R's taken together are dialkyl methylene to form a cyclic diester.

### Claim 4 (depends on 3)

A compound according to claim 3 wherein the two R's are ethyl so that the specific embodiment is diethyl 2-(3-fluorophenyl-4-nitro)-2-methylmalonate.