Cyclization to form cephem ring and intermediates therefor
Abstract
Abstract Intermediates represented by the following formulas are useful for synthesizing 3-hydroxy-3-cephem compounds ##STR1## wherein A and B each is a hydrogen or amino substituent; R is a hydrogen or thiol substituent; Hal is a halogen; X is a hydroxy or carboxy protecting group; the broken line between A and R shows that when R and B are hydrogens, and A is a carboxylic acyl, the substituents can be combined to form an azetidinothiazoline bicyclic ring; and the enamine derivatives thereof. One embodiment provides for cyclizing a compound of the formula: ##STR2## wherein A, B, X and Hal are as defined above, which comprises treating the said compound with an acid, base, or solvent if required in the presence of a catalyzer to give a compound represented by following formula ##STR3## In a further embodiment a compound represented by the following formula ##STR4## wherein A, B, R and X are as defined above, is prepared by a process which comprises treating an enamine of a compound represented by following formula ##STR5## wherein A, B, R, X, Hal and broken line are as defined above, with a disubstituted amino containing from 2 to 20 carbon atoms, with the action of an aqueous acid.
Inventors
- 👤 Teruji Tsuji
- 👤 Yoshio Hamashima
- 👤 Mitsuru Yoshioka
- 👤 Masayuki Narisada
- 👤 Hiroshi Tanida
- 👤 Taichiro Komeno
- 👤 Wataru Nagata
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |