摘要:
The present invention relates to novel processes for the preparation of 3-methylenecephams. More specifically, the present invention relates to the intramolecular cyclization of penicillin sulfoxide derived monocyclic azetidinone derivatives with organometallic catalysts of the formula III. MEx(H2O)y (III) wherein: M is Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Zr, Hf, Th, Nb, Ta, U, Bi, or In; E is O[SO2(C1-C6 polyfluoroalkyl)], N[SO2(C1-C6 polyfluoroalkyl)]2, or C[SO2(C1-C6 polyfluoroalkyl)]3; x is 3; y is 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9.
摘要:
2,5-Disubstituted oxazolidin-4-one-3-ylacetyl chlorides and 1,2,5-substituted imidazolidin-4-one-3-yl-acetyl chlorides function as chiral auxiliary moieties in the asymmetric cycloaddition with aldimines to provide cis-azetidinones. The azetidinones are useful intermediates in the preparation of antibiotics.
摘要:
1-[.alpha.-(Carboxy)-4-hydroxybenzyl]-3.beta.-aminoazetidin-2-one esters are prepared by converting 2-acyl-3,3-dialkyl-7-oxo-.alpha.-[4-(benzyloxy)phenyl]-4-thia-2,6-diazabicyclo[3.2.0]heptane-6-acetic acid esters with mercuric acetate in an aqueous organic solvent mixture, e.g., in aqueous methanol, to 7-oxo-3-phenyl-.alpha.-[4-(benzyloxy)phenyl]-4-oxa-2,6-diazabicyclo[3.2.0]hept-2-ene-1-acetic acid esters and the latter are reacted with PCl.sub.5 and pyridine to provide the monocyclic 1-[.alpha.-(carboxy)-4-benzyloxybenzyl]-3.beta.-(.alpha.-chlorobenzylideneamino)-4-chloroazetidin-2-one esters. Reduction of the dichloro azetidin-2-one with an organo tin hydride and azobisisobutyronitrile affords the deschloro, 1-[.alpha.-(carboxy)-4-benzyloxybenzyl]-3.beta.-benzylideneaminoazetidin-2-one ester. The latter is hydrolyzed and the benzyloxy group is cleaved via catalytic hydrogenolysis to yield an ester of 1-[.alpha.-(carboxy)-4-hydroxybenzyl]-3.beta.-aminoazetidin-2-one. The 3.beta.-amino ester is useful for the preparation of the antibiotic FR 1923 (nocardicin).
摘要:
Process for 1-[.alpha.-(carboxy)-4-hydroxy or protected-hydroxybenzyl]-3-acylamidoazetidin-2-one esters, useful intermediates for preparing antibiotic FR 1923, comprising the ring opening of a 2-acyl-3,3-dialkyl-7-oxo-.alpha.-[4-(protected-hydroxyphenyl]-4-thia-2,6-diazabicyclo[3.2.0]heptane-6-acetic acid, ester sulfoxide with a sulfonic acid and heat to provide a 3-acylamido-4-(2-oxaalkylthio)azetidin-2-one ester which on treatment with sulfuryl chloride affords a reaction product mixture that is then reduced with an organo tin hydride, e.g., tri(n-butyl)tin hydride, to the product. N-Deacylation of the 3-acylamido group followed by acylation with the 3-acyl portion of FR 1923, deblocking of the amino-protecting group and deesterification affords FR 1923.
摘要:
7-(4-Hydroxyphenylglycylamido)-3-(1-methyl-1H-tetrazolyl-5-thiomethyl)-3-cephem-4-carboxylic acid, 7-(4-hydroxyphenylglycylamido)-3-(5-methyl-1,3,4-thiadiazolyl-2-thiomethyl)-3-cephem-4-carboxylic acid, the corresponding 3-hydroxy isomers and the pharmaceutically acceptable, non-toxic salts thereof are orally effective antibiotics exhibiting high blood levels.
摘要:
The present invention provides glycopeptide antibiotic derivative compounds. These derivative compounds possess antibacterial activity against a wide variety of bacteria, including activity against vancomycin-resistant isolates. Methods of making and using these glycopeptide antibiotic derivative compounds are also provided.
摘要:
The present invention provides glycopeptide antibiotic derivative compounds. These derivative compounds possess antibacterial activity aginst a wide variety of bacteria, including activity against vancomycin-resistant isolates. Methods of making and using these glycopeptide antibiotic derivative compounds are also provided.
摘要:
3.beta.-Substituted succinimido)azetidinones represented by the formula ##STR1## wherein R and R.sub.1 are e.g. C.sub.1 -C.sub.5 alkanoyloxy, benzoyloxy, substituted benzoyloxy, or benzyloxy, or one of R and R.sub.1 is hydrogen and the other is as defined above; R.sub.2 is C.sub.1 -C.sub.4 alkoxycarbonyl or an arylvinyl group e.g. styrryl or 2-furylvinyl; and R.sub.3 is e.g. protected-carboxymethyl, or an NH protecting group; are provided via stereoselective cycloaddition of imines with chiral auxiliary 3,4-disubstituted succinimidoacetyl chlorides. The chiral auxiliary e.g., 3S,4S-dibenzoyloxy-and 3S,4S-diacetoxysuccinimidoacetyl chloride, is obtained from tartaric acid via anhydride and imide formation with retention of chirality. The chiral azetidinones obtained are useful intermediates to .beta.-lactam antibacterial compounds.
摘要:
Naphthylglycyl and tetrahydronaphthylglycyl cephalosporins are potent antibacterial agents and are particularly useful as oral treatments for upper respiratory infections.