Patent US2789132A successfully refreshed from Google Patents.
US2789132A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of sulphamic acids
Assignee: —
•
Filing: —
•
Granted: 1957-04-16
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Expires: 1974-04-16
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:35
CPC Classifications
C; C07; C07C; C07C307/00; C07C307/02; C07C309/00; C07C309/01; C07C309/28; C07C309/57
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
A PROCESS FOR THE PREPARATION OF SULPHAMIC ACIDS WHICH COMPRISES SULPHONATING A MEMBER SELECTED FROM THE GROUP CONSISTING OF THE PRIMARY AND SECONDARY AROMATIC AMINES CONTAINING A NITRO GROUP, SUING AS THE SULPHONATING AGENT AN ADDITION PRODUCT OF SULPHURIC ANHYDRIDE ON A MEMBER SELECTED FROM THE GROUP CONSISTING OF 2-METHYL PYRIDINE, 2:6-DIMETHYL PYRIDINE AND MIXTURES THEREOF.
Claim 2
Dependent Claim
56 words
A PROCESS FOR THE PREPARATION OF SULPHAMIC ACIDS WHICH COMPRISES SULPHONATING A MEMBER SELECTED FROM THE GROUP CONSISTING OF THE PRIMARY AND SECONDARY AROMATIC AMINES CONTAINING A NITRO GROUP, SUING AS THE SULPHONATING AGENT AN ADDITION PRODUCT OF SULPHURIC ANHYDRIDE ON A MEMBER SELECTED FROM THE GROUP CONSISTING OF 2-METHYL PYRIDINE, 2:6-DIMETHYL PYRIDINE AND MIXTURES THEREOF.
References Cited (Backward Citations)
GB298550A
Cited
US2247921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-04-15 | 1960-10-15 | 1961-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-15 | 1964-10-15 | 1965-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-15 | 1968-10-15 | 1969-04-16 | $7700.00 | Window Closed / Lapsed |