Efficient catalyst-free Domino approach for the synthesis of novel 2-benzazepine derivatives in water (original) (raw)
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The 1 H NMR and 13 C NMR spectra were recorded at 400 MHz and 100 MHz, respectively. The chemical shifts are reported in ppm downfield to TMS (δ = 0) for 1 H NMR and relative to the central CDCl 3 resonance (δ = 77.0) for 13 C NMR. In the 13 C NMR spectra, the nature of the carbons (C, CH, CH 2 or CH 3) was determined by recording the DEPT-135 experiment, and is given in parentheses. The coupling constants J are given in Hz. Column chromatography was performed using Acme's silica gel (particle size 0.063-0.200 mm). High-resolution mass spectra were recorded on micromass ESI-TOF MS. GCMS mass spectrometry was performed on Shimadzu GCMS-QP2010 mass spectrometer. IR spectra were recorded on JASCO FT/IR-5300. Elemental analyses were recorded on a Thermo Finnigan Flash EA 1112 analyzer. Mass spectra were recorded on either VG7070H mass spectrometer using EI technique or Shimadzu-LCMS-2010 A mass spectrometer. The X-ray diffraction measurements were carried out at 298 K on an automated Enraf-Nonious MACH 3 diffractometer using graphite monochromated, Mo-Kα (λ = 0.71073 Å) radiation with CAD4 software or the X-ray intensity data were measured at 298 K on a Bruker SMART APEX CCD area detector system equipped with a graphite monochromator and a Mo-Kα fine-focus sealed tube (λ = 0.71073 Å). For thin-layer chromatography (TLC), silica gel plates Merck 60 F254 were used and compounds were visualized by irradiation with UV light and/or by Supplementary Material (ESI) for Organic & Biomolecular Chemistry This journal is (c) The Royal Society of Chemistry 2009 S-2 treatment with a solution of p-anisaldehyde (23 mL), conc. H 2 SO 4 (35 mL), acetic acid (10 mL), and ethanol (900 mL) followed by heating. Materials: All solvents and commercially available chemicals were used as received. Hagemann's esters 1a-m was prepared from alkyl acetoacetates and aldehydes with high yields in one-step according to our recent modified method. 1 Hagemann's ester 1n was prepared from benzylidene acetone with high yield in two-steps according to literature procedures (see Scheme S1). 2 Hagemann's ester 1o was prepared from trimethyl-(1methylene-allyloxy)-silane and propynoic acid ethyl ester with high yield in two-steps according to literature procedure (see Scheme S2). 2c General Experimental Procedures for the Synthesis of Highly Functionalized 5,6-Dihyro-2H-Benzo[b][1,4]oxazocines: The syntheses of highly functionalized 5,6-dihyro-2H-Benzo[b][1,4]oxazocines from corresponding Hagemann's esters involves the following three-steps.