Abstract: The present invention relates to a new one-pot process for preparing 2'-(diethylamino)rifamycin P and its 25-desacetyl derivative which consists in cyclizing 3-bromorifamycin S or its 25-desacetyl derivative, dissolved in dimethylformamide, with 1,1-diethylthiourea and reducing, without isolation, the obtained 1,2-quinonimine intermediate with a mild reducing agent.

Abstract: A solid rifapentine hydrohalide useful for anti-bacterial purposes.

Abstract: The invention relates to novel acyl derivatives of rifamycins of the formula ##STR1## and the salts thereof, in which the structural elements --A.sub.1 --A.sub.2 --, --A.sub.3 --A.sub.4 -- and --A.sub.5 --A.sub.6 -- each denote ethylene or vinylene or the elements --A.sub.1 --A.sub.2 -- and --A.sub.3 --A.sub.4 -- each denote ethylene and --A.sub.5 --A.sub.6 -- denotes vinylene; X represents >C(R.sub.6)-- or >N-- and R.sub.6 denotes hydrogen or alkyl; alk denotes an aliphatic hydrocarbon radical; R.sub.1 denotes hydrogen or acyl; R.sub.2 denotes acyl, or alkyl which is optionally substituted by an aromatic radical, and R.sub.3 and R.sub.3 ' represent a common bond, or R.sub.3 denotes hydrogen or acyl, and R.sub.3 ' is hydrogen; R.sub.4 denotes hydrogen, cycloalkyl or aryl; R.sub.5 denotes hydrogen or acetyl; R.sub.7 denotes hydrogen or alkyl, which can be used as active compounds in medicaments, the preparation and use thereof, and pharmaceutical products and the preparation thereof.

Abstract: The non-solvated crystalline form "A" of 3-(-4-cynnamyl-1-piperazinyl)-iminomethylrifamycine SV finds application in the therapeutical practice.It represents a crystalline substance with absorption maximum of the infrared spectrum at 1644, 1585, 1340, 1350, 1295 and 1290-doublet, 1238, 1213, and triplet with low intesitivety at 726, 735 and 760 cm.sup.-1, as well as with characteristic diffraction maxima at 9,25 and 9,50 .theta.--most-intensive at 12,22 and doublet at 13,10 and 13,33 .theta. of the X-ray diffraction diagram.The obtaining of the non-solvated crystalline form "A" consists in the isolation of 3-(-4-cynnamyl-1-piperazinyl)-iminomethylrifamycine obtained in medium of indifferent organic solvent, preferably tetrahydrofuran or chloroform, and its dissolution in isopropanol or acetone or a mixture of both at a temperature from 30.degree. C. up to the ebullition temperature of the respective solvent.

Abstract: 3-W-Rifamycin SV and S compound, wherein W is a piperazin-1-yl radical of the formula ##STR1## wherein R.sup.1 and R.sup.2 are C.sub.1 -C.sub.4 alkyl and R.sup.3, R.sup.4 and R.sup.5 are hydrogen or C.sub.1 -C.sub.4 alkyl, or R.sup.2 together with R.sup.3 or R.sup.3 together with R.sup.4 are buta-1,3-dien-1,4-ylene, trimethylene or tetramethylene, each of which is unsubstituted or substituted by C.sub.1 -C.sub.4 alkyl, and R.sup.1, R.sup.4 and R.sup.5 or R.sup.1, R.sup.2 and R.sup.5 are hydrogen or C.sub.1 -C.sub.4 alkyl, and salts thereof, have long-term antituberculotic and antimicrobial activity.

Abstract: The present invention concerns new 2'-substituted-4-deoxy-thiazolo[5,4-c]rifamycin SV derivatives having antibacterial activity.These compounds are compounds obtained by chemical modification of thiazolo[5,4-c]rifamycin SV.

Abstract: Rifamycin derivatives of formula ##STR1## wherein R is a radical of the formula ##STR2## in which R.sub.1 is an unsubstituted or substituted biphenylyl radical, and wherein X--X, Y--Y and Z--Z are each vinylene of the formula CH.dbd.CH, or wherein X--X and Y--Y are each ethylene of the formula CH.sub.2 --CH.sub.2 and Z--Z is ethylene or vinylene, and processes for the preparation thereof are described. These compounds can be used as antibacterial and antiviral medicaments.

Abstract: The present invention provides expellants of phytopothogenic microbes comprising rifamycins, which have excellent in prevention of disease in plants with little adverse influence to human body and environments.

Abstract: Novel hydrazones derived from 3-formylrifamycin S or SV as the aldehydo component and a bi- or tri-cyclic N-aminopiperazine as the hydrazino component and having the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6, independently of one another, each represents a hydrogen atom or C.sub.1-4 -alkyl,m and n, independently of one another, each represents an integer from 0 to 5,X represents C.sub.1-5 -alkylidene, benzylidene or C.sub.1-4 -alkoxymethylene,Y represents C.sub.1-5 -alkylidene, C.sub.1-4 -alkoxymethylene, oxy, thio or optionally substituted imino of the formula --N(R)-- wherein R represents hydrogen, C.sub.1-4 -alkyl, C.sub.3-5 -alkenyl, C.sub.3-12 -cycloalkyl or phenyl, orX and Y together represent 1,2-cycloalkylene or o-phenylene each of which can be substituted by from one to three C.sub.