Alpha t ft ir spectrometer

Solvents were purchased from commercial suppliers and used as received, without purification. The synthesis of 5-(2-Hydroxy-6-oxocyclohexyl)-5H-chromeno[2,3-b]pyridine-3-carbonitriles 1 was performed in accordance with the following methods [54 (link),55 (link)].
Using Gallenkamp melting-point apparatus (Gallenkamp & Co., Ltd., London, UK), melting points were measured. At room temperature, ¹H and ¹³C-NMR spectra were obtained in DMSO-d₆ with a Bruker AM300 spectrometer (Bruker Corporation, Billerica, MA, USA). The values for chemical shift are given in relation to Me₄Si. A Bruker AV500 spectrometer (Bruker Corporation, Billerica, MA, USA) was used to record two-dimensional (2D) NMR spectra. A Bruker AV400 spectrometer (Bruker Corporation, Billerica, MA, USA) was used to register the ¹H-NMR monitoring spectra. IR spectra were determined with a Bruker ALPHA-T FT-IR spectrometer (Bruker Corporation, Billerica, MA, USA) in KBr pellets. With a Kratos MS-30 spectrometer (Kratos Analytical Ltd., Manchester, UK), mass spectra (EI = 70 eV) were acquired. For elemental analysis, a 2400 Elemental Analyzer (Perkin Elmer Inc., Waltham, MA, USA) was applied.

The solvents and reagents were purchased from commercial sources and used as received. 2-Aminoprop-1-ene-1,1,3-tricarbonitrile (malononitrile dimer) 2 was synthesized from malononitrile according to the literature [46 (link)].
All melting points were measured with a Gallenkamp melting-point apparatus (Gallenkamp & Co., Ltd., London, UK) and were uncorrected. ¹H and ¹³C-NMR spectra were recorded in DMSO-d₆ with Bruker AM300 and Bruker AV500 spectrometers (Bruker Corporation, Billerica, MA, USA) at ambient temperature. Chemical shift values are relative to Me₄Si. Some ¹H-NMR spectra have underestimated NH₂ signals integrals. These protons were exchanged with D₂O (it is present as an impurity in DMSO-d₆). Two-dimensional (2D) NMR spectra were registered with a Bruker AV400 spectrometer (Bruker Corporation, Billerica, MA, USA) at ambient temperature. The IR spectrum was recorded with a Bruker ALPHA-T FT-IR spectrometer (Bruker Corporation, Billerica, MA, USA) in a KBr pellet. MS spectra (EI = 70 eV) were obtained directly with a Kratos MS-30 spectrometer (Kratos Analytical Ltd., Manchester, UK). High-resolution mass spectra (HRMS) were measured on a Bruker micrOTOF II (Bruker Corporation, Billerica, MA, USA) instrument using electrospray ionization (ESI).

The solvents and reagents were purchased from commercial sources and used as received. 2-Aminoprop-1-ene-1,1,3-tricarbonitrile 2 was obtained from malononitrile according to the literature [24 (link)].
All melting points were measured with a Gallenkamp melting-point apparatus (Gallenkamp & Co., Ltd, London, UK) and were uncorrected. ¹H and ¹³C-NMR spectra were recorded in DMSO-d₆ with Bruker AM300, Bruker AV500, and Bruker AV600 spectrometers (Bruker Corporation, Billerica, MA, USA) at ambient temperature. Chemical shift values are relative to Me₄Si. Two-dimensional (2D) NMR spectra were registered with a Bruker AV500 spectrometer. 1H NMR monitoring spectra were registered with a Bruker AM300 spectrometer (Bruker Corporation, Billerica, MA, USA). The IR spectrum was recorded with a Bruker ALPHA-T FT-IR spectrometer (Bruker Corporation, Billerica, MA, USA) in a KBr pellet. MS spectra (EI = 70 eV) were obtained directly with a Kratos MS-30 spectrometer (Kratos Analytical Ltd, Manchester, UK). High-resolution mass spectra (HRMS) were measured on a Bruker micrOTOF II (Bruker Corporation, Billerica, MA, USA) instrument using electrospray ionization (ESI).