Stereospecific synthesis of azeto[2,1‐d]‐ [1,5]benzothiazepin/diazepin‐1‐ones

Abstract

Abstract2a,4‐Disubstituted 2‐phenoxy‐2,2a,3,4‐tetrahydro‐1H‐azeto[2,1‐d][1,5]benzothiazepin‐1‐ones and 5‐benzoyl‐2‐phenoxy‐2a,3,4,5‐tetrahydro‐azeto[1, 2‐a][1,5]benzodiazepin‐1(2H)‐ones were synthesized in moderate to good yields by stereospecific Staudinger cycloaddition reactions of 2,4‐disubstituted 2,3‐dihydro‐1,5‐benzothiazepines and 1‐benzoyl‐2,3‐dihydro‐1H‐1,5‐benzodiazepines, respectively, with phenoxy acetyl chloride in the presence of triethylamine in anhydrous benzene. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:564–569, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10196

Synthesis of novel β-lactam-fused 1,5-benzothiazepine derivatives bearing quinoline moiety

“…Eventually, the zwitterionic intermediate (6) may proceed via conrotatory ring closure to form a β-lactam ring (7), which simultaneously undergoes conformation transfer to produce finally the predominant chair-like products (5).…”

“…Finally, to build up a β-lactam derivative library of dihydrobenzothiazepines, 1,5-benzothiazepines were reacted with various acyl chlorides, including chloroacetyl chloride and phenoxyacetyl chloride, in the presence of triethylamine, to give the target compounds (5). But the yield was poor, possibly because of a complicated mixture of products when the reaction was carried out at reflux temperature [32].Various analytical techniques, such as IR, 1 H-NMR, mass spectrum, and elemental analysis were utilized to confirm the structural identities of the final products.…”

“…Up to now, some β-lactams fused to a five or six-membered heterocyclic ring containing nitrogen and sulfur atoms (penicillin, penam and penem) have been synthesized by various methods [3][4][5][6].…”

Synthesis of novel spiro fused polycyclic β-lactam derivatives

“…In the same way, spiro-fused β-lactams 2b,c and amides 3b,c together with recovered starting materials were obtained from 1,5-benzothiazepines 1b,c (Entries 4 and 5, Table 1). In our previous investigation, 23,24,27 the reaction of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines 1 with monosubstituted ketenes, generated from substituted acetyl chlorides in the presence of triethylamine gave β-lactam derivatives in good to excellent yields. The lower yields of β-lactams 2 in the current cases are possibly due to steric hindrance of the disubstituted ketene, pentamethyleneketene,…”

“…derivatives of benzothiazepines, benzodiazepines, and dibenzo[b,f]oxazepines because of their potential biological and pharmaceutical importance. [22][23][24][25][26][27][28][29] Up to now, a few examples of spirofused β-lactam derivatives of 1,4-benzodiazepines have been prepared via the Staudinger reaction. 30 In continuation of our efforts to prepare structurally diverse β-lactam derivatives of benzoheteroazepines, we set out to synthesize some novel spiro-fused polycyclic β-lactam derivatives for bioassay of antibacterial activity in response to the growing resistance of bacteria against penicillin and cephalosporin-like compounds and the request for medicines with a more specific antibacterial activity or other biological activities.…”