Vinylsulphonylpristinamycin and its preparation

Organic compounds -- part of the class 532-570 series – Organic compounds – Unsubstituted hydrocarbyl chain between the ring and the -c-...

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C07D49814, A61K 3142

Patent

active

052722660

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates to a new pristinamycin II.sub.B derivative of formula: ##STR1## as well as to their preparation.


BACKGROUND OF THE INVENTION

Pristinamycin II.sub.B derivatives have been described previously in American Patents U.S. Pat. No. 4,590,004 and U.S. Pat. No. 4,668,669. These products have the property of synergizing the antimicrobial activity of pristinamycin I.sub.A.
Vinyl sulphones are useful products as synthesis intermediates, especially in carrying out Michael reactions. Their preparation is generally performed in several steps, among which an oxidation step and often the isolation of an intermediate sulphone take place, since the preparation is performed in most cases by proceeding via a thiol.


DESCRIPTION OF THE INVENTION

It is found that the vinyl sulphone of formula (I) could be obtained in high yield in one oxidation step, after introducing the sulphur bearing an appropriate functional group at the .beta.-position.
According to the invention, the vinyl sulphone derived from pristinamycin II.sub.B may be prepared by oxidation of a 26-[2-(dialkylamino)ethylthio]pristinamycin II.sub.B of general formula: ##STR2## in which Alk is an alkyl radical containing 1 to 4 carbon atoms in a straight or branched chain, with 4 to 6 equivalents of hydrogen peroxide in the presence of a catalyst such as ammonium molybdate or sodium tungstate.
This new technique has the advantage of being very gentle and very specific. It may hence be applied to delicate molecules containing a large number of functions capable of being adversely affected by the reaction, as is the case with the component II of pristinamycin.
The reaction is performed in an alcohol, such as, for example, ethanol, methanol or isopropanol, at a temperature of between -25.degree. and +25.degree. C. The quantity of catalyst, expressed in moles % is introduced in the proportion of 1 to 7 % of the starting thioether.
It is essential to work in the presence of a large excess of hydrogen peroxide: in the proportion of 4 to 6 equivalents per mole of sulphide employed in the reaction. Preferably, the reaction is performed in the presence of 5 equivalents of oxidizing agent.
In the case of a reaction catalyzed by sodium tungstate, it is understood that the reaction may be carried out at low temperature, but it is necessary for the last part of the reaction to be carried out at a temperature not below 0.degree. C.
Another advantage of the new process according to the invention is that of enabling vinyl sulphones derived from pristinamycin II.sub.B to be obtained in high yields and without subsequent purification.
The 26-[2-(dialkylamino)ethylthio]pristinamycin II.sub.B of general formula (II) may be obtained as described in U.S. Pat. No. 4,590,004.
The vinyl sulphone according to the invention is useful as an intermediate for the preparation of pristinamycin II.sub.B derivatives of general formula: ##STR3## in which R is a linear or branched alkyl radical containing 1 to 10 carbon atoms, by the action of the amine of general formula:
The reaction is generally performed in a chlorinated solvent such as, for example, methylene chloride, at a temperature of between 0.degree. and 25.degree. C.
The pristinamycin derivatives of general formula (III) are especially advantageous products which are described in U.S. Pat. No. 4,668,669 for their antibacterial activity and their synergistic action on the antibacterial activity of natural pristinamycin I.sub.A, virginiamycin S and soluble derivatives of these products.


EXAMPLE

The examples which follow, given without implied limitation, illustrate the present invention.


EXAMPLE 1

65.9 g (0.1 mol) of 26-[2-(diethylamino)thio]pristinamycin II.sub.B are placed in 400 cm.sup.3 of ethanol and cooled to -20.degree. C. The oxidizing agent (ammonium molybdate: 8.65 g, 7 % +hydrogen peroxide (30 %): 51.5 cm.sup.3, 5 eq.) is added in the course of 20 minutes at between -20.degree. and -15.degree. C. and stirring is continued for 40 minutes at -20.degree. C. In the course o

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Vinylsulphonylpristinamycin and its preparation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Vinylsulphonylpristinamycin and its preparation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vinylsulphonylpristinamycin and its preparation will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-310160

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.