US4123435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitro-substituted benzoxazoles having utility as metallurgical extractants
Assignee: Dow Chemical Co
•
Filing: 1977-08-25
•
Granted: 1978-10-31
•
Expires: 1997-08-25
Abstract
Abstract Nitro-substituted 2-(2-hydroxyphenyl)benzoxazoles of the formula ##STR1## wherein one of R 3 and R 4 is --NO 2 and the other is --H, --NO 2 or alkyl of 1 to 20 carbons and R 1 and R 2 independently are --H or alkyl of 1 to 20 carbons, with the proviso that R 1 , R 2 , R 3 and R 4 contain a total of at least 7 carbons, are acidic, oil soluble compounds having utility for extraction of copper from strongly acidic ore leaches. Excellent selectivity for copper over iron is exhibited by the subject compounds.
Inventors
- 👤 Robert R. Grinstead
- 👤 Kenneth C. Jones
- 👤 Wilmonte A. Nasutavicus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:46
CPC Classifications
C; C07; C07D; C07D263/00; C07D263/52; C07D263/54; C07D263/56; C07D263/57; C01; C01G; C01G3/00; C01G3/003; C22; C22B; C22B3/00; C22B3/20; C22B3/26; C22B3/36; C22B3/362; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S423/00; Y10S423/09; Y10S423/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
68 words
A benzoxazole of the formula ##STR7## wherein: one of R 3 and R 4 is NO 2 and the other is H, NO 2 or alkyl of 1 to 20 carbons, and R 1 and R 2 independently are H or alkyl of 1-20 carbons, with the proviso that R 1 , R 2 , R 3 and R 4 contain a total of at least 7 carbons.
Claim 2
Dependent Claim
68 words
A benzoxazole of the formula ##STR7## wherein: one of R 3 and R 4 is NO 2 and the other is H, NO 2 or alkyl of 1 to 20 carbons, and R 1 and R 2 independently are H or alkyl of 1-20 carbons, with the proviso that R 1 , R 2 , R 3 and R 4 contain a total of at least 7 carbons.
Claim 3
Dependent Claim
24 words
A compound as defined in claim 1 wherein R 1 , R 2 , R 3 and R 4 contain at least 8 carbons.
Claim 4
Dependent Claim
32 words
A compound as defined in claim 1 wherein R 3 and R 4 are both --NO 2 groups and R 1 and R 2 contain a total of at least 12 carbons.
Claim 5
Dependent Claim
23 words
A compound of claim 2 in which each of R 1 and R 2 is an alkyl group of 4 or more carbons.
Claim 6
Dependent Claim
19 words
A compound of claim 2 wherein R 3 is H or alkyl and R 4 is NO 2 .
Claim 7
Dependent Claim
29 words
The compound of claim 5 in which each of R 1 , R 2 is a t-butyl group, R 3 is H and R 4 is NO 2 .
Claim 8
Dependent Claim
26 words
The compound of claim 2 in which each of R 1 , R 2 and R 3 is t-butyl and R 4 is NO 2 .
References Cited (Backward Citations)
US3655347A
Cited
US4020081A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-30 | 1982-05-01 | 1982-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-30 | 1986-05-01 | 1986-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-30 | 1990-05-01 | 1990-10-31 | $7700.00 | Window Closed / Lapsed |