# US 4,395,556 A · Nitrobenzofurazan derivatives

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,395,556 A
- Document ID: US4395556A
- Status: Granted
- Kind: A
- Application number: 06/345,883
- Filed: 1982-02-04
- Granted: 1983-07-26
- Earliest claimed: 1982-02-04
- Assignees: E. R. Squibb & Sons, Inc.
- Inventors: Callixtus E. Ita; Anthony F. Heald; Peter Egli
- Web page: https://patentgrep.com/patent/US4395556A

## CPC

- C07D 413/12: linked by a chain containing hetero atoms as chain links
- Y10S 436/80: Fluorescent dyes, e.g. rhodamine
- Y10S 436/826: Additives, e.g. buffers, diluents, preservatives
- Y10T 436/13: Tracers or tags
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Nitrobenzofurazan derivatives having the formula ##STR1## are provided wherein R.sub.1 and R.sub.2 each is hydrogen, lower alkyl or phenyl-lower alkyl; R.sub.3 is hydrogen, hydroxy or lower alkyl; R.sub.4 is hydrogen or lower alkyl; m is 2 or 3; and n is 0, 1 or 2; these compounds are useful analytical tools.

## Claims

### Claim 1

A compound having the formula ##STR10## or a salt thereof, wherein R.sub.1 and R.sub.2 each is hydrogen, lower alkyl or phenyl-lower alkyl; R.sub.3 is hydrogen, hydroxy or lower alkyl; R.sub.4 is hydrogen or lower alkyl; m is 2 or 3; and n is 0, 1 or 2.

### Claim 2 (depends on 1)

A compound in accordance with claim 1 wherein R.sub.4 is hydrogen.

### Claim 3 (depends on 1)

A compound in accordance with claim 1 wherein R.sub.1 is methyl, n is 1, m is 2 and R.sub.2 and R.sub.3 are each hydrogen.

### Claim 4 (depends on 1)

The compound in accordance with claim 1 having the name 1-[2-methyl-3-[(4-nitrobenzofurazan-7-yl)thio]-1-oxopropyl]-L-proline.