52094-02-7Relevant articles and documents
Benzylic Phosphates in Friedel-Crafts Reactions with Activated and Unactivated Arenes: Access to Polyarylated Alkanes
Pallikonda, Gangaram,Chakravarty, Manab
, p. 2135 - 2142 (2016/03/15)
Easily reachable electron-poor/rich primary and secondary benzylic phosphates are suitably used as substrates for Friedel-Crafts benzylation reactions with only 1.2 equiv activated/deactivated arenes (no additional solvent) to access structurally and electronically diverse polyarylated alkanes with excellent yields and selectivities at room temperature. Specifically, diversely substituted di/triarylmethanes are generated within 2-30 min using this approach. A wide number of electron-poor polyarylated alkanes are easily accomplished through this route by just tuning the phosphates.
Highly efficient method for solvent-free synthesis of diarylmethane and triarylmethane from benzylic alcohols using P2O5/Al 2O3 or P2O5/SiO2 at room temperature
Khazaei, Ardeshir,Rad, Mohammad Navid Soltani,Borazjani, Maryam Kiani,Moradian, Khadijeh Mansouri,Borazjani, Mohammad Kiani,Zebarjadian, Mohammad Hassan
experimental part, p. 120 - 126 (2012/06/18)
A highly efficient procedure for the synthesis of triarylmethane and diarylmethane via benzylation of aromatic hydrocarbons from benzyl alcohols using supported P2O5 on SiO2 and/or Al 2O3 under solvent-free conditions is described. Excellent yields of triarylmethane and diarylmethane were obtained using P 2O5-SiO2 (50%W/W) and/or P2O 5-Al2O3 (50%W/W) at room temperature. The reusability of both supported P2O5 on SiO2 and Al2O3 were examined. Both supported reagents show favorable activities in first and second runs, however, a decline in reactivity was observed in following attempts. The reaction is scalable to > 0.03 mole amounts.
Selective preparation of 4,4′-dichlorodiphenylmethane over zeolite K-L catalyst using sulfuryl chloride
Kale,Singh
, p. 399 - 411 (2008/10/08)
The liquid phase chlorination of diphenylmethane (DPM) to 4,4′-dichlorodiphenylmethane (4,4′-DCDPM) is investigated at 333 K, under atmospheric pressure over a number of zeolite catalysts using sulfuryl chloride (SO2Cl2) as the chlorinating agent. The results obtained are compared with those over the conventional Lewis acid catalyst, AlCl3 as well as without any catalyst. Zeolite K-L is found to be highly active and selective catalyst for the conversion of DPM to 4,4′-DCDPM. The conversion of DPM, rate of DPM conversion and the selectivity (4,4′-DCDPM/2,4′-DCDPM isomer ratio) over zeolite K-L after 1 h of reaction time are found to be 96.8 wt.%, 19.1 mmol g-1 h-1 and 7.4, respectively. The influence of solvent, catalyst concentration, reaction temperature, DPM/SO2Cl2 molar ratio, recycle of zeolite K-L, etc. are also examined. 1,2-Dichloroethane is the best solvent and gives the highest selectivity for 4,4′-DCDPM (4,4′-DCDPM/2,4′-DCDPM isomer ratio = 9.7) with zeolite K-L at 353 K after 1 h of reaction time. The formation of 4,4′-DCDPM is favoured by increase in catalyst concentration, reaction temperature and higher concentration of SO2Cl2 (lower DPM/SO2Cl2 molar ratio). In all these cases, the yield of 4,4′-DCDPM increases with a decrease in the yield of 4-CDPM which suggests that the formation of 4,4′-DCDPM takes place by the consecutive reaction of 4-CDPM. Higher SiO2/Al2O3 ratio (obtained by HCl treatment) of zeolite K-L decreases the conversion of DPM. A noticeable decrease in the activity and selectivity of zeolite K-L is observed on recycling, probably due to reduced crystallinity as well as extraction of small amounts of Al+3 and K+ ions by the HCl, generated in the reaction. Mechanistically, SO2Cl2 is first decomposed into SO2 and Cl2 the latter being polarized by the zeolite catalyst to an electrophile (Cl+) which then attacks the DPM and subsequently produce the monochlorodiphenylmethane (MCDPM). The MCDPM further is attacked by the electrophile (Cl+) and result in the formation of DCDPM.
Abnormal Friedel-Crafts Reactions: Intermediacy of Aryl-aluminium Dichloride Complex in Reactions with Benzyl Chlorides
Apte, D. V.,Deodhar, K. D.
, p. 758 - 759 (2007/10/02)
Diphenylmethane is reported as one of the products in the Friedel-Crafts reaction between o-xylyl chloride and benzene, where only o-benzyltoluene is expected.Mechanism of formation of diphenylmethane is suggested and intermediacy of aryl-AlCl3 complex and methylene chloride is proved by chemical evidence.The reaction is shown to be a general reaction of benzyl chlorides.
