Synthesis of tethered indoles in the search for conformationally controlled calixindoles: an indole 3-substituent tether

3-(2-Hydroxyphenyl)-4,6-dimethoxyindole 8 has been synthesised and linked to 1,3,5-tribromomethylbenzene and 1,2,4,5-tetrabromomethylbenzene to give the tri-indolyl and tetra-indolyl compounds 18 and 23, respectively. Attempts to generate capped calix[3]indoles and calix[4]indoles from these compounds were unsuccessful.