HYDROXYLATED PCB DERIVATIVES - SYNTHESIS AND STRUCTURE ELUCIDATION BY NMR-SPECTROSCOPY AND X-RAY-DIFFRACTION

Structures of eight PCB derivatives: 2',3,4',5',6-pentachloro-2-biphenylol (1), 2,2',4',5,5'-pentachloro-3-biphenylol (2), 2,2',4',5,5'-pentachloro-4-biphenylol (3), 2',4,4',5,5',6-hexachloro-2-biphenylol (4), 2',3',4,4',5,6,6'-heptachloro-2-biphenylol (5), 2,2',3',4,4',5,5'-heptachloro-3-biphenylol (6), 2,2',3,3',4',5,5'-heptachloro-4-biphenylol (7) and 2',3',4,4',5,5',6,6'-octachloro-2-biphenylol (8) have been elucidated by use of H-1 NMR chemical shift assignment of 1-8, a heteronuclear C-12-H-1 chemical shift correlation spectroscopy (C,H-COSY) experiment on 1. mass spectra and high resolution mass spectra of 1-8 and X-ray crystallographic analysis of 4 and 8. All compounds were synthesized by a modification of the aromatic arylation method of Cadogan by coupling the corresponding chloroaniline and chloroanisole in the presence of isoamyl nitrite, followed by demethylation with boron tribomide in CH2Cl2. Compound 4 crystallizes in the monoclinic space group P2(1)/n (No. 14) with cell dimensions: a = 8.988(2), b = 19.490(3) and c = 10.722(2) angstrom and V = 1813.8(5) angstrom-3 with Z = 4. Full-matrix least-squares refinement of 208 parameters gave R = 0.048 for 2195 reflections [I > 3sigma(I)]. Compound 8 crystallizes in the triclinic space group P1 (No. 2) with cell dimensions: a = 8.440(2), b = 7.726(2) and c = 13.328(3) angstrom and V = 780(1) angstrom-3 with Z = 2. Full-matrix least-squares refinement of 190 parameters give R = 0.057 for 1551 reflections [I > 3sigma(I)].