Indene dimerization products

Abstract

The reaction of 1H-indene (indene) in the presence of Friedel-Crafts acids was studied. As expected [M. Spiteller, J. Jovanović, Fuel 78(1999)1263] there were dimers and trimers in the product mixture together with higher oligomers. Among products with double molecular weight relative to the molecular weight of indene, the structure of four compounds was determined: 6-(2’,3’-dihydro-1’H-inden-1’-yl)-1H-indene 2-(2’,3’-dihydro-1’H-inden-1’-yl)-1H-indene 1-(2’,3’-dihydro-1’H-inden-2’-yl)-1H-indene and 2,3,1’,3’-tetrahydro-[1,2’]biindenylidene. It was shown that the first one represents an indene alkylation product and that the others were obtained by bonding of the indan-1-ylium ion and indene at the position 2, followed by acid catalyzed 1,2-hydride rearrangement in the case of the third and fourth one. Considering the indene dimerization products as components of pyrolysis oils and as interesting compounds to be used as model substances for NMR, MS and X-ray analysis, the reaction, separation and isolation parameters were optimized in this study.

Ispitivana je reakcija 1H-indena u prisustvu Fridel-Kraftsovih kiselina. Kao što je i očekivano,1 smeša proizvoda je sadržala dimere, trimere i više oligomere. Među proizvodima sa dvostrukom molskom masom, u odnosu na molsku masu indena, određena je struktura četiri jedinjenja 6-(2’,3’-dihidro-1’H-inden-1’-il)-1H-indena 2-(2’,3’-dihidro-1’H-inden-1’-il)-1H-indena 1-(2’,3’-dihidro-1’H-inden-2’-il)-1H-indena i 2,3,1’,3’-tetrahidro-[1,2’]biindenilidena. Pokazano je da je prvo jedinjenje proizvod alkilacije indena, a da su preostala tri dobivena povezivanjem indena u položaju 2 sa indan-1-ilijum jonom, pri čemu je u slučaju trećeg i četvrtog jedinjenja došlo i do 1,2-hidridnog premeštanja. Uzimajući u obzir da su proizvodi dimerizacije indena komponente pirolitičkih ulja i interesantna jedinjenja kao modeli za NMR i MS analize i analize pomoću X-zraka, u ovom radu je optimizirano njihovo dobijanje, razdvajanje i izolovanje.