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Process for the preparation of sterically uniform, natural 6-thiatetracycline derivatives
| Details |
Inventors: Kirchlechner, Richard;
Assignee: Merck Patent Gesellschaft mit beschrankter Haftung (Darmstadt, DE)
Primary Examiner: Randolph; John D.
Assistant Examiner:
Attorney, Agent or Firm: Millen & White
A process for the preparation of racemic 6-thiatetracycline derivatives comprises treating a mixture of epimers of corresponding 1,4,4a,5,5a,6,11,12a-octahydro-3,12-dihydroxy-1,11-dioxo-6-thianaphthacene -2-carboxamides with a saturated heterocyclic secondary amine having a total of 4 to 12 carbon atoms for a sufficient length of time at temperatures of about 15.degree.-120.degree. C. |
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DETAILED DESCRIPTION What is claimed is: 1.
A process for the preparation of racemic sterically uniform 6-thiatetracycline derivatives of "natural" configuration which comprises treating a mixture of epimers of corresponding 1,4,4a,5,5a,6,11,12a-octahydro-3,12-dihydroxy-1,11-dioxo-6-thia-naphthacen e-2-carboxamides with a saturated heterocyclic amine having a total of 4 to 12 carbon atoms and one ring N atom at a temperature of about 15.
degree.
-120.
degree.
C.
for a length of time effective to produce said racemic sterically uniform derivatives of "natural" configuration.
2.
The process of claim 1 wherein the time/temperature relation is about 12 hours at 20.
degree.
C.
and about 1 hour at 50.
degree.
C.
3.
The process of claim 1 wherein the epimerization is conducted at a temperature of 20.
degree.
-70.
degree.
C.
4.
The process of claim 1 wherein the base is piperidine, morpholine or pyrrolidine.
5.
The process of claim 4 wherein the base is piperidine.
6.
The process of claim 5 wherein the epimerization is conducted at a temperature of 50.
degree.
-70.
degree.
C.
for 75 minutes - 10 minutes.
7.
The process of claim 1 wherein the epimerization is conducted under a nitrogen atmosphere.
8.
The process of claim 1 wherein the 6-thiatetracycline derivative is a racemate consisting of compounds of the formula ##STR5## wherein R.
sup.
1, R.
sup.
2 and R.
sup.
4 each is H or alkyl; R.
sup.
3 is H, F, Cl, Br, CF.
sub.
3, OH, alkyl, alkoxy, NO.
sub.
2, NH.
sub.
2, alkylamino, dialkylamino or acylamino; Z is a functionally modified amino group; and alkyl and alkoxy each is of 1-3 carbon atoms and acyl is of 1-4 carbon atoms, and the optical antipodes thereof.
Description:
BACKGROUND OF THE INVENTION The present invention relates to a novel process for the preparation of racemates consisting of 6-thiatetracycline derivates of "natural" configuration and their optical antipodes.
Hereinafter, the term "6-thiatetracycline" is used to refer to a racemate which consists of 4-dimethylamino-1,4,4a,5,5a,6-11,12a-octahydro-3,10,12,12a-tetrahydroxy-1, 11-dioxo-6-thia-naphthacene-2-carboxamide having the configuration indicated in the formula
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Manufacturing Materials 
