3-[1-(4-Bromo-phen-yl)eth-oxy]-2,2,5-trimethyl-4-phenyl-3-aza-hexa-ne.

The title compound, C22H30BrNO, is an alk-oxy-amine compound, an effective initiator in nitroxide-mediated free radical polymerization. It was prepared as a mixture of two diasteromers; the crystal for the X-ray analysis showed one of these as a pair of R,S and S,R enanti-omers. The tert-butyl and isopropyl groups are in an almost anti conformation in the crystal [C-N-C-C torsion angle = -168.8 (1)°], and the methyl group of the ethoxy group is in an approximate anti relationship to the tert-butyl group. The dihedral angle between the phenyl and benzene rings is 33.12 (7)°. The Br atom is disordered over two positions, with occupancies of 0.9139 (16) and 0.0861 (16). In the crystal, weak C-H⋯Br contacts link the mol-ecules into chains along [-110].