GB1244019A - Urea-antibiotic adducts and process for preparing the same - Google Patents

Abstract

1,244,019. Macrolide-urea adducts. ELI LILLY & CO. 4 Dec., 1968 [4 Dec., 1967 (2); 15 July, 1968], No. 57629/68. Heading C2A. Novel aldehydic-rnacrolide bis-ureas wherein the aldehyde group of 1 molecule of an appropriate macrolide is combined with 2 molecules of a urea of formula wherein Am is -NH-R, R being phenyl, tolyl, halophenyl or trifluoromethylphenyl; or R<SP>1</SP> and R<SP>11</SP> being independently hydrogen, C 1 to C 4 alkyl or C 3 to C 4 alkenyl and the sum of their carbon atoms not exceeding 4, are prepared by reacting in a neutral solvent, at least 2 moles of the urea with 1 mole of the macrolide. The macrolides may be tylosin, macrosin, desmycosin, lactenocin, carbomycin, carbomycin B, niddamycin, spiramycins A, B, C and D or leucomycins A 1 to A 8 . Ureas may be urea or N-methyl-; N,N-diethyl-; N-n-butyl-; N- allyl-; N-phenyl-; N-(p-chlorophenyl)-; N-(otolyl)-; or N- (p .trifluoromethylphenyl)-urea. The compounds are preferably prepared by adding the macrolide or a salt thereof to a saturated aqueous or alcoholic solution of the urea at room temperature, allowing to stand, diluting with water and bringing to pH 9, and saturating the solution with sodium chloride to precipitate the required product. This is filtered off, dissolved in chloroform, the solution washed with water, and the chloroform evaporated off; the product is finally recrystallized, e.g. from aqueous acetone. Dihydro (ketone reduced) tylosin bis-urea is prepared by reducing tylosin bis-urea in ethanolic solution with sodium borohydride, and is subsequently hydrolysed by treatment with aqueous ethanol at pH 5À0 and 90‹ C. for ¢ hour to give the novel antibiotic dihydro- (ketone reduced) tylosin, this product being extracted from the reaction solution with methyl - ene dichloride at pH 5À0 to 5À5. Alternatively, the dihydro (ketone-reduced) bis-urea is hydrolysed to give the novel antibiotic dihydro/ketone-reduced) desmycosin by aqueous hydrolysis at either pH 2À8 and room temperature for 4 days or pH 3À6 and 100‹ C. for 1¢ hours, the said antibiotic being extracted from the hydrolysate with methylene dichloride at pH 7 to 8. Pharmaceutical compositions comprise one or both of the antibiotics dihydro(ketone-reduced) tylosin and dihydro(ketone-reduced) desmycosin together with a carrier. Veterinary compositions for administering to ruminants comprise an aldehydic-macrolide bis-urea as defined above together with a carrier which may be an animal feedstuff.