Mercuration of Diazomethane

Abstract

As a possible route to bis-oxymethylmercury acetate, Hg(CH₂CO₂CH₃)₂, we have examined the reaction of diazomethane with mercuric acetate. Although a reaction has been stated to occur¹ no details of the products were reported. The reaction in ether was slow and heterogeneous. There was no evidence of methylenation of the mercury–oxygen bond, as apparently occurs with arylmercury benzoates², nor of reduction to mercurous acetate. Instead, when diazomethane (0.03 M) was slurried in ether with dry mercuric acetate (0.015 M), methyl acetate was formed (50 per cent after one day, 90 per cent after five days), together with an insoluble and dangerously explosive pale yellow solid (90 per cent), and small amounts of a soluble yellow oil. This oil, obtained by evaporation of the filtrate and separation from polymethylene on a short silica-gel column, is apparently bisdiazomethylmercury, Hg(CHN₂), analogous to the long known bis(carboxyethyldiazomethyl)mercury³, Hg(CN₂CO₂Et)₂, although the yield (5 per cent) is much lower. It showed a strong localized absorption at 2,105 cm⁻¹, indicating a diazoalkane grouping, and evolved nitrogen with acids. Bromine decolorized it, giving mercuric bromide, nitrogen and some bromoform.