US4122092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Total synthesis of (±)-picropodophyllone and (±)-4'-demethylpicropodophyllone
Assignee: University of Rochester
•
Filing: 1977-08-25
•
Granted: 1978-10-24
•
Expires: 1997-08-25
Abstract
Abstract Efficient total syntheses of (±)-picropodophyllone and (±)-4'-demethylpicropodophyllone are described. These compounds are intermediates in the preparation of known antineoplastic agents.
Inventors
- 👤 Andrew S. Kende
- 👤 Peter S. Rutledge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:27
CPC Classifications
C; C07; C07D; C07D493/00; C07D493/02; C07D493/04; C07D317/00; C07D317/08; C07D317/44; C07D317/46; C07D317/48; C07D317/50; C07D317/60; C07D317/70
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
The process for the preparation of a compound of the formula ##STR18## wherein R 2 is (lower)alkyl, which comprises treating a compound of the formula ##STR19## in which R 2 is as defined above, in an inert organic solvent, with from about 1 to about 2 molar equivalents of thallium (III) trifluoroacetate in the presence of an excess of a Lewis acid, at a temperature of from about 10° to about 35°, reducing the excess thallium (III) trifluoroacetate with a mild reducing agent and recovering the desired product from the reaction mixture.
Claim 2
Dependent Claim
92 words
The process for the preparation of a compound of the formula ##STR18## wherein R 2 is (lower)alkyl, which comprises treating a compound of the formula ##STR19## in which R 2 is as defined above, in an inert organic solvent, with from about 1 to about 2 molar equivalents of thallium (III) trifluoroacetate in the presence of an excess of a Lewis acid, at a temperature of from about 10° to about 35°, reducing the excess thallium (III) trifluoroacetate with a mild reducing agent and recovering the desired product from the reaction mixture.
Claim 3
Dependent Claim
39 words
The process of claim 1 wherein the Lewis acid is AlCl 3 , ZnCl 2 or boron trifluoride etherate and is utilized in an amount of from about 1 to about 10 moles per mole of thallium (III) trifluoroacetate.
Claim 4
Dependent Claim
60 words
The process of claim 2 wherein the mild reducing agent is (a) sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, sodium thiosulfate, potassium thiosulfate, sulfur dioxide, stannous chloride or zinc metal, or (b) KI, NaI or LiI followed by sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, sodium thiosulfate, potassium thiosulfate, stannous chloride or zinc metal to reduce free iodine.
Claim 5
Dependent Claim
62 words
The process of claim 3 wherein the Lewis acid is boron trifluoride etherate and the mild reducing agent is (a) sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, sodium thiosulfate, potassium thiosulfate or sulfur dioxide, or (b) KI, NaI or LiI followed by sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, sodium thiosulfate, potassium thiosulfate or sulfur dioxide to reduce free iodine.
Claim 6
Dependent Claim
13 words
The process of claim 4 wherein the Lewis acid is boron trifluoride etherate.
Claim 7
Dependent Claim
10 words
The process of claim 5 wherein R 2 is ethyl.
Claim 8
Dependent Claim
25 words
The process of claim 6 wherein the reaction is conducted at about room temperature for a period of from about 4 to about 18 hours.
References Cited (Backward Citations)
GB1088621A
Cited
US4059593A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-23 | 1982-04-24 | 1982-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-23 | 1986-04-24 | 1986-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-23 | 1990-04-24 | 1990-10-24 | $7700.00 | Window Closed / Lapsed |