... R Compound C2 C (4,6) C5 Reference "Chemical shifts in ppm relative to DMSO-d6 at 39.5 ppm. bPh: o, 127.8; m, 128.9; p, 131.7; i, 132.3; ortho and meta assignments are interchangeable. ... 4. (a) TB JOHNSON. J. Ind. ... In Thorpe's Dictionary of Applied Chemistry. 4th ed. Vol. 10. ...