Organomercury Compounds .XXVIII. The Synthesis and ¹⁹⁹Hg N.M.R-Spectra of Some Unsymmetrically Dimercurated Arenes

Abstract

Mercuration of 1-methoxy-2-nitrobenzene (1) with mercuric trifluoroacetate (mole ratio 1 : 1) in trifluoroacetic acid yields 1- methoxy-2-nitro-4-(trifluoroacetatomercurio)benzene (2). With a 1 : 2 mole ratio, (2) and 1-methoxy-2-nitro-4,6- bis(trifluoroacetatomercurio)benzene (3) are obtained, and, with a 1:4 ratio, (3) and a little 1-methoxy-2-nitro-3,4- bis(trifluoroacetatomercurio)benzene (4). are obtained. 2-Nitrophenol (5) with mercuric trifluoroacetate (mole ratio 1 : 2) gives 2-nitro- 4,6-bis(trifluoroacetatomercurio)phenol (6), and vanillin (7) yields 5,6-bis(trifluoroacetatomercurio)vanillin (8). Compound (8) has been converted into 5,6-di(chloromercurio)- and 5,6- di(bromomercurio)vanillin [(9) and (10)]. ¹⁹⁹Hg,¹⁹⁹Hg spin-spin coupling constants have been determined s 6500-8200 Hz for ³J_Hg,Hg of (8)- (10), 2100-2200 Hz for ⁴J_Hg,Hg of (3) and (6), and 858 Hz for ⁵J_Hg,Hg of 4- methoxy-2,5-bis(trifluoroacetatomercurio)benzoic acid (11).