5274-70-4Relevant articles and documents
Synthesis, characterization, and photochromism study of two spiropyran molecules with a terminal alkynyl functional group and their new 1,2,3-triazoline-containing derivatives
Mahdavian, Ali Reza,Nasr-Isfahani, Hossein,Notash, Behrouz,Sepehr, Zeinalabedin
, (2021/10/19)
The spiropyran derivatives are known for their good photochromic properties. These photochromic compounds are isomerized between two forms; merocyanine is the open-ring form and spiropyran is the closed-ring form. In this work, two spiropyran derivatives (compounds 1 and 2) with the N-alkynyl functional group are prepared. The click reactions of these spiropyran derivatives with 1-azido-4-nitrobenzene and (azidomethyl)benzene are studied. For this purpose, 3,3-dimethyl-2-methylene-1-prop-2-ynyl-2,3-dihydro-1H-indole is synthesized, which is then reacted with 3- and 5-nitrosalicylaldehyde. The FT-IR, 1H-NMR, and 13C-NMR spectra of the reaction products are used for their characterization. The solutions of the products in methanol are prepared, and their UV–visible spectra are investigated. The darkening of the crystals of compound 1 upon exposure to the UV irradiation indicates that the spiro C–O bond in this compound is weaker than that in compound 2, which is due to the presence of the nitro group in the para position relative to this bond, and consequently, the stabilization of the open-ring form.
Nitration under continuous flow conditions: Convenient synthesis of 2-isopropoxy-5-nitrobenzaldehyde, an important building block in the preparation of nitro-substituted Hoveyda-Grubbs metathesis catalyst
Knapkiewicz, Pawel,Skowerski, Krzysztof,Jaskolska, Dagmara E.,Barbasiewicz, Michal,Olszewski, Tomasz K.
, p. 1430 - 1435 (2012/11/07)
Herein, we describe the use of continuous flow chemistry for selective, efficient and reproducible nitration of 2-isopropoxybenzaldehyde to produce the desired 2-isopropoxy-5-nitrobenzaldehyde, an important building block in the preparation of a ligand of nitro-substituted Hoveyda-Grubbs metathesis catalyst. Nitration was done with red fuming HNO3, and this challenging and hazardous process was performed using a flow-through silicon-glass microreactor equipped with a set of temperature sensors, and with a productivity of 13 g/h, providing us with a reproducible chemical process amenable for production of sufficient quantities of 2-isopropoxy-5-nitrobenzaldehyde for ongoing large-scale synthesis of nitro-substituted Hoveyda-Grubbs metathesis catalyst.
Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
Aridoss, Gopalakrishnan,Laali, Kenneth K.
experimental part, p. 8088 - 8094 (2011/11/13)
Acting as in situ sources of triflyl nitrate (TfONO2) and trifluoroacetyl nitrate (CF3COONO2), the EAN/Tf 2O and EAN/TFAA systems, generated via metathesis in the readily available ethylammonium nitrate (EAN) ionic liquid as solvent, are powerful electrophilic nitrating reagents for a wide variety of aromatic and heteroaromatic compounds. Comparative nitration experiments indicate that EAN/Tf2O is superior to EAN/TFAA for nitration of strongly deactivated systems. Both systems exhibit low substrate selectivity (K T/KB = 5-10) in (Figure presented) between values reported for covalent nitrates and preformed nitronium salts.
