摘要:
N-Mono or N-disubstituted methyl-2-azetidinones are provided via cyclization of .beta.-hydroxy or .beta.-halo substituted acid sec-amides wherein the amide nitrogen is substituted with a mono- or di-substituted methyl group having activating substituents. Cyclization of .beta.-hydroxy acid amides is mediated by triphenylphosphine-dialkylazodicarboxylate while cyclization of .beta.-halo acid amides is mediated by strong bases e.g. lithium dialkylamides. E.g. Diethyl amino-protected L-serylaminomalonate is cyclized with 200 mole % TPP-diisopropylazodicarboxylate to N-(diethoxycarbonylmethyl)-3-protected-amino-2-azetidinone. The 2-azetidinones provided are useful intermediates.
摘要:
Embodiments relate to the field of chemistry and biochemistry, and, more specifically, to imidazopyridine compounds, synthesis thereof, and methods of using same. Disclosed herein are various imidazo[1,2-a]pyhdine compounds and methods of using the novel compounds to treat or prevent tuberculosis in a subject or to inhibit fungal growth on plant species. Other embodiments include methods of synthesizing imidazo[1,2-a]pyridine compounds, such as the disclosed imidazo[1,2-a]pyridine compounds.
摘要:
Embodiments relate to the field of chemistry and biochemistry, and, more specifically, to anti-cancer compounds, synthesis thereof, and methods of using same. Disclosed herein are various heterocyclic compounds and methods of using the novel anti-cancer compounds to inhibit the growth of a cancer cell, for instance a leukemia, non-small cell lung, central nervous system (CNS), skin, ovarian, renal, prostate, breast, or colon cancer cell. Other embodiments include methods of treating cancer in a subject, such as using the disclosed heterocyclic anti-cancer agents.
摘要:
Substituted 2-(azetidin-2-on-1-yl)alkoxyalkylalkanoic acids and 2-(azetidin-2-on-1-yl)arylalkylalkanoic acids, and analogs and derivatives thereof are described. Methods for using the described compounds, and pharmaceutical compositions thereof, to treat disease states responsive to antagonism of one or more vasopressin receptors are also described.
摘要:
Substituted 2-(azetidin-2-on-1-yl)alkoxyalkylalkanoic acids and 2-(azetidin-2-on-1-yl)arylalkylalkanoic acids, and analogs and derivatives thereof are described. Methods for using the described compounds, and pharmaceutical compositions thereof, to treat disease states responsive to antagonism of one or more vasopressin receptors are also described.
摘要:
Bicyclic .beta.-lactams comprising a 5- or 6-membered lactone or lactam ring are obtained in a process comprising a base induced intramolecular cyclization of a 4-substututed .beta.-lactam having a leaving group in the 1-position. An intramolecular nucleophile transfer reaction is proposed as the operative mechanism and the bicyclic .beta.-lactams are obtained in the required stereochemical form for biological activity. The compounds provided are useful intermediates for the preparation of antibiotics and .beta.-lactamase inhibitors.
摘要:
Monocyclic .beta.-lactam compounds represented by the formula ##STR1## wherein R.sub.1 is H, NH.sub.2, acylamino, C.sub.1 -C.sub.4 alkyl, etc.; R.sub.2 is e.g. C.sub.1 -C.sub.4 alkyl, hydroxyalkyl, aminoalkyl, carboxy, esterified carboxy, esterified carboxyalkyl, or carboxyalkyl; and R.sub.3 is hydrogen, benzyl, substituted benzyl, pivaloyl, --SO.sub.3 M, or --P(C.dbd.O)(OM')2; are obtained by the cyclization of an O-substituted hydroxamate of a .beta.-substituted alkylcarboxylic acid. For example, .alpha.-ethylmalic acid monobenzyl ester is reacted with O-benzylhydroxylamine to form the O-benzylhydroxamate of the free carboxy group, and the hydroxamate is cyclized with diethyl diazodicarboxylate and triphenylphosphine to form the .beta.-lactam of the above formula wherein R.sub.1 is ethyl, R.sub.2 is benzyloxycarbonyl and R.sub.3 is benzyl. The .beta.-lactam compounds are useful intermediates for preparing .beta.-lactamase inhibitors and monocyclic .beta.-lactam antibiotics and, when R.sub.3 is --SO.sub.3 M or --P(C.dbd.O)(OM')2 the compounds and salts thereof are antibacterial agents.
摘要:
A stereoselective process for chiral intermediates to 1-carbapenum and 1-carbacephalosporins is provided comprising the use of an N-acyl-(4R)-substituted-1,3-thiazolidine-2-thione as a chiral auxiliary in boron enolate mediated aldol condensation with a protected-.beta.-keto ester aldehyde. E.g., benzyl 3,3-(ethylenedioxy)-4-formylbutyrate is condensed with the boron enolate formed with n-butyryl (4R)-methoxycarbonyl-1,3-thiazolidine-2-thione to provide benzyl 3,3-ethylenedioxy-(5R)-hydroxy-6-[(4R)-methoxycarbonyl-1,3-thiazolidine-2-thione-3-ylcarbonyl]octanoate. Displacement of the thiazolidine-2-thione chiral auxiliary moiety with an O-alkyl, O-acyl or O-aralkyl hydroxyamine provides the corresponding chiral intermediate as the hydroxamate.
摘要:
Process for N-acyloxy or sulfooxy 2-azetidinones comprising O-acylation of a .beta.-hydroxy or .beta.-halo hydroxamic acid, and cyclizing the O-acylhydroxamate with TPP-CCl.sub.4 -TEA or with TPP-dialkylazodicarboxylate to the N-acyloxy-2-azetidinone. Solvolysis of the acyl group provides an N-hydroxy-2-azetidinone. e.g., N-Cbz-L-serine is converted to the O-acetyl hydroxamate, cyclized and solvolyzed to N-hydroxy-3-(Cbz-amino)-2-azetidinone. The N-hydroxy-2-azetidinones are useful intermediates to monocyclic .beta.-lactam antibiotics and .beta.-lactamase inhibitors.
摘要:
0-lactamyl alkanoic acids are described. Methods for treating various premenstrual disorders using or more β-lactamyl alkanoic acids are also described.