Patent US3553541A successfully refreshed from Google Patents.
Patent US4797477A successfully refreshed from Google Patents.
US4797477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing sialic acid derivatives
Assignee: Mect Corp
•
Filing: 1987-08-11
•
Granted: 1989-01-10
•
Expires: 2007-08-11
Abstract
Abstract The present invention relates to a new process for preparing 3-O-(sodium(5-acetamide-3,5-dideoxy-alpha-D-glycero-D-galacto-2-noneuro pyranosyl)onate-1,2-di-O-tetradecyl-Sn-glycerol (3) consisting essentially of hydrolyzing a 3-O-(C 1-5 alkyl(5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-di-deoxy-alpha-D-glycero-D-galacto-2-noneuropyranosyl)onate)-1,2-di-O-tetradecyl-Sn-glycerol (1) in a single step, in an aqueous lower aliphatic alcohol solution of an alkali metal hydroxide.
Inventors
- 👤 Shoji Yoshimura
- 👤 Yoichiro Tani
- 👤 Youzi Matsuzaki
- 👤 Masayoshi Ito
- 👤 Yoshiyasu Shitori
- 👤 Tomoya Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:17
CPC Classifications
C; C07; C07H; C07H15/00; C07H15/02; C07H15/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
A process for preparing a compound represented by the formula: ##STR9## wherein Ac is acetyl and Alk is an alkali metal, consisting essentially of: hydrolyzing, in a single step, a compound of the formula: ##STR10## wherein Ac is as defined above and R is C 1-5 alkyl, in an aqueous ROH solution of an alkali metal hydroxide.
Claim 2
Dependent Claim
57 words
A process for preparing a compound represented by the formula: ##STR9## wherein Ac is acetyl and Alk is an alkali metal, consisting essentially of: hydrolyzing, in a single step, a compound of the formula: ##STR10## wherein Ac is as defined above and R is C 1-5 alkyl, in an aqueous ROH solution of an alkali metal hydroxide.
Claim 3
Dependent Claim
12 words
The process as described in claim 1, wherein the ROH is methanol.
Claim 4
Dependent Claim
15 words
The process as described in claim 1, wherein the alkali metal hydroxide is sodium hydroxide.
Claim 5
Dependent Claim
19 words
The process as described in claim 3, wherein a concentration of the aqueous sodium hydroxide solution is from 0.5-2N.
Claim 6
Dependent Claim
26 words
The process as described in claim 3, wherein the sodium hydroxide is used in an amount of 3-10 moles to 1 mole of the compound 1.
Claim 7
Dependent Claim
23 words
The process as described in claim 1, wherein the compound (1) is dissolved in a lower aliphatic alcohol or THF solvent before hydrolyzing.
Claim 8
Dependent Claim
12 words
The process as described in claim 4, wherein the solvent is methanol.
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) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |