β-Lactamase-stable penicillins. Synthesis and structure–activity relationships of (Z)-alkyloxyimino penicillins; selection of BRL 44154

Abstract

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Synthesis, in Vitro Antimycobacterial and Antibacterial Evaluation of IMB-070593 Derivatives Containing a Substituted Benzyloxime Moiety

“…Reduction of various benzaldehydes 1a – d with sodium borohydride in methanol gave the phenylmethanols 2a – d , and then 2a – d and commercially available compounds 2e – m were coupled with 2-hydroxyisoindoline-1,3-dione in the presence of diethylazodicarboxylate (DEAD) and triphenylphosphine (PPh 3 ) in tetrahydrofuran to produce condensates 3a – m . The desired compounds 4a – m were obtained by treatment of 3a – m with hydrazine hydrate in dichloromethane according to well established procedures [ 22 ].…”

Design, Synthesis, and in vitro Antibacterial Activity of Fluoroquinolone Derivatives Containing a Chiral 3‐(Alkoxyimino)‐2‐(aminomethyl)azetidine Moiety

“…[11] Treatment of l/d-serine (S)/(R)-4 with di-tert-butyl dicarbonate (Boc 2 O) in dioxane gave Boc-protected compound (S)/(R)-5, [12] and the hydroxy group of (S)/(R)-5 was subsequently protected by reaction with tert-butyldiphenylchlorsilane (TBDPSCl) in DMF in the presence of imidazole to yield serine derivative (S)/(R)-6, in an overall yield of 73-74 % for the two steps. N-Hydroxyphthalimide 1 was treated with bromoalkanes (RBr) in N,N-dimethylformamide (DMF) in the presence of 18-crown-6 and potassium carbonate at 80 8C, and the resulting condensates 2 a-e were subsequently treated with hydrazine hydrate in dichloromethane/ methanol to produce the desired compounds 3 a-e by following well-established procedures.…”

“…N-Hydroxyphthalimide 1 was treated with bromoalkanes (RBr) in N,N-dimethylformamide (DMF) in the presence of 18-crown-6 and potassium carbonate at 80 8C, and the resulting condensates 2 a-e were subsequently treated with hydrazine hydrate in dichloromethane/ methanol to produce the desired compounds 3 a-e by following well-established procedures. [11] Treatment of l/d-serine (S)/(R)-4 with di-tert-butyl dicarbonate (Boc 2 O) in dioxane gave Boc-protected compound (S)/(R)-5, [12] and the hydroxy group of (S)/(R)-5 was subsequently protected by reaction with tert-butyldiphenylchlorsilane (TBDPSCl) in DMF in the presence of imidazole to yield serine derivative (S)/(R)-6, in an overall yield of 73-74 % for the two steps. [13] (S)/ (R)-6 was treated with isobutyl chloroformate in the presence of N-methylmorpholine (NMM) to give a mixed anhydride, which was then treated with diazomethane to afford diazoketone (S)/(R)-7 in 68-71 % yield.…”

Synthesis of 17β-Hydroxy Esters of 4-Estren-17β-ol-3-one and Carbenicillin, Ticarcillin, or Functionalized Oxacillin: Potentially Useful Conjugates for β-Lactamase-Based Homogeneous Immunoassays

“…Therefore, a hemisynthesis of these substances has been tried using a modifed side chain by conjugation to nandrolone. The hemisynthesis of penicillin from a side chain and from 6-aminopenicillanic acid is often carried out in two steps (3,7). The carboxylic acid function on the side chain is first activated into an acyl chloride or a mixed anhydride or by using a dioxanedione cycle (meldrum acid) (13), before coupling to 6-aminopenicillanic acid.…”

“…Conjugation of penicillins to proteins or polymers has been carried out after activation of the carboxyl groups present on the thiazole ring or in the side chain (3,4). In several procedures, native or introduced thiols have also been used for this purpose (5,6).…”