Preparation and NMR Analysis of 2,6-Heterodifunctional Halobenzenes as Precursors for Substituted Biphenyls

Preparation and complete characterization of 16 2,6-disubstituted halobenzenes, including nine new compounds, from two common starting materials is described. Seven of the new compounds contain one or two propylthio groups, which have been introduced in two ways. Direct reaction of arenediazonium salts with 1-propanethiolate gives yields comparable to those obtained in a three-step method through sulfonyl chlorides. The 1H- and 13C NMR chemical shifts of 17 1,2,3-trisubstituted benzenes have been correlated with the predicted values and the observed trends explained using commonly available modeling packages.