Novel rifamycin compounds of high antibiotic activity

A method of preparing a rifamycin compound, wherein a compound having the formula:

• ##STR7## wherein Y is --H or --COCH.sub.3, its 16, 17, 18, 19 tetrahydroderivatives and 16, 17, 18, 19, 28, 29 hexahydroderivatives, is reacted in the presence of acetic acid and a metal selected from the group comprising zinc and iron with an aldehyde having the formula
• X--CHO
• wherein X is a radical selected from the group comprising hydrogen, carboxyl, alkyl with less than 10 carbon atoms, cycloalkyl with less than 7 carbon atoms, alkenyl with less than 4 carbon atoms, cycloalkenyl with less than 7 carbon atoms, aryl hydrocarbon with less than 13 carbon atoms, aryl hydrocarbon-alkyl with less than 14 carbon atoms, aryl hydrocarbon-alkenyl with less than 11 carbon atoms, a hetercycle selected from the group comprising thiophene, furan, thiazole, thionaphtene, methylene dioxphenyl and pyridine, substitution products of the above specified radical with a substituent which is at least one radical different thereform and selected from the group comprising, in addition to all of the above specified radical, halogen, hydroxyl, alkoxyl, nitro, amino, N-alkylamino, N,N-dialkylamino, formyl, carboxyl, carboalkoxy, carboxyalkoxy, N-N-dialkylaminoalkoxy, alkanoyloxy and acetamido, there being less than 14 carbon atoms in said radical X.

A method of preparing a rifamycin compound, wherein 3-amino-rifamycin S having the formula:

• ##STR8## wherein Y is --H or --COCH.sub.3, its 16, 17, 18, 19 tetrahydroderivatives and 16, 17, 18, 19, 28, 29 hexahydroderivatives, is reacted in a solvent selected from the group comprising ethers and aromatic hydrocarbons with ammonia gas and an aldehyde having the formula:
• X--CHO
• wherein X is a radical selected from the group comprising hydrogen, carboxyl, alkyl with less than 10 carbon atoms, cycloalkyl with less than 7 carbon atoms, alkenyl with less than 4 carbon atoms, cycloalkenyl with less than 7 carbon atoms, aryl hydrocarbon with less than 13 carbon atoms, aryl hydrocarbon-alkyl with less than 14 carbon atoms, aryl hydrocarbon-alkenyl with less than 11 carbon atoms, a hetercycle selected from the group comprising thiophene, furan, thiazole, tetrazole, thionaphtene, methylene dioxyphenyl and pyridine selected from the group comprising, substitution products of the above specified radicals with a substituent which is at least one radical different therefrom and selected from the group comprising, in addition to all of the above specified radicals, halogen, hydroxyl, alkoxyl, nitro, amino, N-alkylamino, N,N-dialkylamino, formyl, carboxyl, carboalkoxy, carboxyalkoxy, N,N-dialkylaminoalkoxy, alkanoyloxy and acetamido, there being less than 14 carbon atoms in said radical X.

A method of preparing a rifamycin compound, wherein a compound of formula (III) ##STR9## wherein Y is --H or --COCH.sub.3. and its 16, 17, 18, 19 tetrahydroderivatives and 16, 17, 18, 19, 28, 29 hexahydroderivatives is reacted in the presence of zinc and acetic acid with a derivative halogen of formula

• X--CH.sub.2 --Hal
• wherein X is a radical selected from the group comprising hydrogen, carboxyl, alkyl with less than 10 carbon atoms, cycloalkyl with less than 7 carbon atoms, alkenyl with less than 4 carbon atoms, cycloalkenyl with less than 7 carbon atoms, aryl hydrocarbon with less than 13 carbon atoms, aryl hydrocarbon-alkyl with less than 14 carbon atoms, aryl hydrocarbon-alkenyl with less than 11 carbon atoms, a hetercycle selected from the group comprising thiophene, furan, thiazole, tetrazole, thionaphtene, methylene dioxyphenl and pyridine, substitution products of the above specified radicals with a substituent which is at least one radical different therefrom and selected from the group comprising, in addition to all of the above specified radical, halogen, hydroxyl, alkoxyl, nitro, amino, N-alkylamino, N,N-dialkylamino, formyl, carboxyl, carboalkoxy, carboxyalkoxy, N,N-dialkylaminoalkoxy, alkanoyloxy and acetamido, there being less than 14 carbon atoms in said radical X.