Efficient one-pot synthesis of 2-azetidinones from acetic acid derivatives and imines using methoxymethylene-N,N-dimethyliminium salt

3-(4-Chlorophenoxy)-1-(4-methoxyphenyl)-4-(4-nitrophenyl)azetidin-2-one

“…For general background to -lactams, see: Banik et al (2004); Garud et al (2009) ;Jarrahpor & Khalili (2007); Jarrahpour & Zarei (2006, 2010. For some of our previous reports of the structures of -lactams, see: Akkurt et al (2008aAkkurt et al ( ,b, 2011a; Baktır et al (2009) ;Yalçın et al (2009) Table 1 Hydrogen-bond geometry (Å , ).…”

“…Data collection: CrysAlis PRO (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009). & Zarei, 2010Banik et al, 2004).…”

One-Pot Sequence Synthesis of Azetidin-2-One Using Diethyl Chlorophosphate

“…Spectral data for 2i-k have been previously reported. 31,40 Synthesis of 2-azetidinones (2a-k); general procedure To a stirred solution of corresponding aldehyde (1.0 mmol) in dry CH 2 Cl 2 (20 mL) at room temperature were successively added the corresponding amine (1.0 mmol) and a large excess of anhydrous sodium sulfate (2.0 g). The resulting mixture was stirred for 24 hours at room temperature.…”

One-step Synthesis of β-lactams Using Cyanuric Fluoride

“…To solve these problems, acid activators have been used for the one-pot synthesis of 2-azetidinones from imines and carboxylic acids. [16][17][18][19][20][21][22] In the present work, cyanuric fluoride is investigated as an acid activator in the synthesis of 2-the azetidinone ring by the ketene-imine cycloaddition.…”

“…26 The mechanism is similar to our previously reported mechanism for the Staudinger reaction from acetic acid derivatives and imines using methoxymethylene-N,N-dimethyliminium salt via formation of an activated form of a carboxylic acid. 20 It is suggested that the reaction is performed by in situ generation of a ketene from the activated ester (Scheme 2), then nucleophile attack of the imine followed by ring closure of the zwitterionic intermediate to the β-lactam. The relative (cis/trans) stereoselectivity is generated as a result of the competition between the direct ring closure and the isomerisation of the imine moiety in the zwitterionic intermediate.…”