Advance 2 400 spectrometer

All precursor chemicals and solvents were procured from Spectrochem Pvt. Ltd (India) and Sigma-Aldrich (India) via commercial vendors in suitable grades and used without further purification. The reactions were conducted with a guard tube containing calcium chloride attached to the reaction flask. The open capillary method was used to determine the uncorrected melting points. A Shimadzu FT-IR 157 spectrometer was used to record the IR spectra. A Bruker Advance II – 400 spectrometer was used to record NMR spectra at 400 MHz for ¹H and at 100 MHz for ¹³C nuclei respectively. Tetramethylsilane (TMS) served as an internal standard. The values of coupling constants (J) and the chemical shifts (δ) are expressed in Hertz and parts per million (ppm) respectively. An Agilent Technology LC-mass spectrometer with ESI ionization was used to record the mass spectra. Elemental analysis was conducted in a CHNS Elementar Vario EL III. Thin-layer chromatography (TLC) was carried out on a silica-coated aluminum sheet (silica gel ⁶⁰F₂₅₄) to monitor the reaction progress and purity of the compounds using ethyl acetate and hexane solvent systems as the mobile phase and visualized under UV light at 254 nm. Column chromatography was performed with 60–120 mesh silica gel. Further for the detailed information please see the ESI file (page no. S10 to S27†).

General information: All the chemicals and solvents were used as received from commercial suppliers, without further purification. The ethyl‐N‐((Z)‐2‐amino‐1,2‐dicyanovinyl)‐formimidate 1, the (Z)‐N′‐(1‐amino‐2,2‐dicyanovinyl)‐N‐aryl/alkylformimidamide derivatives 2 and the 5‐amino‐1H‐imidazole‐4‐carbimidoyl cyanide derivatives 3 used in this work were prepared by previously described procedures.[¹³, ¹⁴, ¹⁵, ¹⁶] The experimental procedures and characterization will only be presented for the new derivatives that were prepared in this work. Cyanoacetamides 7 were also prepared according to a previously described procedure.^[21] Most of the reactions were performed in an IKAMAG RCT basic, at different temperatures with magnetic stirring between 300–500 RPM. The ¹H NMR spectra were recorded in a Bruker Advance II+ 400 spectrometer at 400 MHz, at 20 °C. The ¹³C NMR spectra were obtained in the Bruker spectrometer at 100 MHz. The chemical shifts (δ) were registered in ppm relative to the residual solvent signal (DMSO‐d₆). Infrared spectra were recorded on a FT‐IR Bomem MB 104 spectrometer and samples were prepared as Nujol mulls using NaCl cells. The reactions were monitored by thin layer chromatography (TLC) using silica gel 60 F254 (Merck). The elemental analysis was obtained in a LECO instrument and the melting points were determined in a Stuart SMP3 digital apparatus.