Two Ways of Preparing Benzonitriles Using BrCCl₃–PPh₃ as the Reagent

Abstract

Benzamides were converted into benzonitriles with BrCCl 3 -PPh 3 -Et 3 N in CH 2 Cl 2 in an Appel-type reaction. Benzaldoximes could be transformed to benzonitriles under identical conditions. It was found that the reaction system BrCCl 3 -(2 equiv.)PPh 3 was also suitable for these transformations with PPh 3 replacing Et 3 N.

Use of Triphenylphosphine-Bromotrichloromethane (PPh3-BrCCl3) in the Preparation of Acylhydrazines, N-Methylamides, Anilides and N-Arylmaleimides From Carboxylic Acids

“…Previously, it had been established that the reactions of the modified Appel reagent BrCCl3-PPh3 are similar to those of CCl4-PPh3. This includes the dehydration of aldoximes and amides to nitriles (1) and the amidation of carboxylic acids (4). Only the actual Appel reaction itself, ie., the transformation of alkanols to haloalkanes with BrCCl3-PPh3 is more complex, where under certain conditions the transfer of the bromo-substituent vs. the chloro-substituent is not selective (2).…”

“…Infrared spectra were measured with a Thermo/Nicolet Nexus 470 FT-IR ESP spectrometer and a Perkin Elmer Spectrum Two spectrometer. 1 H and 13 C NMR spectra were recorded with a Varian 400 NMR spectrometer (1H at 395.7 MHz, 13 C at 100.5 MHz). The assignments of the carbon signals were aided by DEPT 90 and DEPT 135 experiments (DEPT = Distortionless Enhancement by Polarisation Transfer).…”

“…134˚C (Lit. 136-137˚C [8]) IR (KBr/cm -1 ) ν 3095, 2936, 2877, 1702, 1518, 1256, 720, 686; 1 Cinnamamide (11a). -A solution of triphenylphosphine (1.89 g, 7.21 mmol) and bromotrichloromethane (BrCCl3, 1.56 g. 7.86 mmol) in dry CH3CN (15 mL) is stirred at rt for 30 min., during which in turns dark yellow.…”

“…Although there are a number of ways to transform carboxylic acids to acyl halides, the reagents needed such as phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphoryl chloride, thionyl chloride and sulfuryl chloride are not always available in certain countries. Against this background, the authors developed the reaction system triphenylphosphine (PPh3)bromotrichloromethane (BrCCl3) to prepare acyl halides in situ [1,2]. This reaction system is a variation of the Appel reagent [3], where tetrachloromethane (CCl4) is replaced by the environmentally less hazardous BrCCl3.…”

Crystal structure of (1Z,2E)-cinnamaldehyde oxime

“…For the other methods of preparation of the title compound, see: Mirjafari et al (2011); Kitahara et al (2008). For the uses of a such compound, see: Narsaiah & Nagaiah (2004); Jasem et al (2014); Garton et al (2010); Patil et al (2012); Kaur et al (2006); Boruah & Konwar (2012 Hydrogen-bond geometry (Å , ).…”