US3697504A
Expired / Lapsed
US
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Process of making purine base nucleoside-5{40 {11 carboxylic acids
Assignee: Zellsloff Fabrik Waldhof AG
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Filing: 1969-07-29
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Granted: 1972-10-10
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Expires: 1989-07-29
Abstract
Abstract Purine-nucleoside-5''-carboxylic acids are made by subjecting a purine-nucleoside, in which the 2'',3''-cis-oriented hydroxy groups are protected by blocking groups, to oxidation with an excess of potassium permanganate in an alkaline aqueous solution, followed by precipitation of the 5''-carboxylic acid. Subsequently the blocking groups may be split off. The compounds are valuable intermediates for making various pharmaceutical products, particularly cancerostatics.
Inventors
- 👤 Robert Richard Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:12
CPC Classifications
C; C07; C07H; C07H19/00; C07H19/02; C07H19/04; C07H19/16; C07D; C07D473/00; C07D473/26; C07D473/28; C07D473/30; C07D473/32; C07D473/34
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
13 words
The process of claim 1, wherein the oxdiation is effected at room temperature.
Claim 2
Dependent Claim
22 words
The process of claim 1, wherein the excess potassium permanganate is eliminated with hydrogen peroxide prior to precipitation of the carboxylic acid.
Claim 3
Dependent Claim
19 words
The process of claim 1, wherein the precipitation of the carboxylic acid is effected by reaction with hydrochloric acid.
Claim 4
Dependent Claim
24 words
The process of claim 1, wherein the pH of the oxidation solution is adjusted to between 4.0 and 4.6 to effect the said precipitation.
Claim 5
Dependent Claim
20 words
The process of claim 1, wherein the blocking groups or group are split off after completion of the oxidation reaction.
Claim 6
Dependent Claim
15 words
The process of claim 1 wherein the blocking group is an isopropylidene or oxy-isopropylidene group.
Claim 7
Dependent Claim
35 words
The process of claim 6, wherein the splitting off of the blocking group is effected by reaction with an aqueous mineral acid followed by neutralization of the mass and precipitation of the unsubstituted purine-nucleoside--5''-carboxylic acid.
Claim 8
Dependent Claim
13 words
The process of claim 8 wherein the mineral acid is aqueous hydrochloric acid.
Claim 9
Dependent Claim
46 words
The process of claim 1, wherein 2'',3''iso-propylidene- or oxy-isopropylidene-substituted inosine or adenosine are dissolved in an aqueous alkaline medium and reacted with an excess of potassium permanganate followed by precipitation of the corresponding 2'',3''-isopropylidene or oxy-isopropylidene-substituted inosine or adenosine--5''-carboxylic acid by reaction with a mineral acid.
Claim 10
Dependent Claim
38 words
The process of claim 10, wherein the 2'',3''-isopropylidene or oxy-isopropylidene-substituted inosine or adenosine-5''-carboxylic acid is subsequently hydrolized with aqueous hydrochloric acid followed by precipitation of the unsubstituted inosine or adenosine 5''-carboxylic acid by neutralizing the acidic hydrolysis solution.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |