4-Arsabenzoic acid

However, in the case of 32f, the elements of diethoxy methyl chloride are lost to give 4-methoxyarsabenzene 33 36). Alternatively, if 32f is reduced to secondary arsine 34, methanol is eliminated to give 35 37>. On hydrolysis, 35 affords 4-arsabenzaldehyde 36. Similarly 32g has been converted to 24g which on hydrolysis gave 4-arsabenzoic acid 37 38 39). 

Although a variety of different functionally substituted arsabenzenes have now been synthesized, to date only 4-arsabenzaldehyde, 4-arsaphenol and the arsabenzoic acids have been extensively studied. 

MO calculations have indicated that the 3-position of arsabenzene is the most electropositive 66,69). The observation that 3-arsabenzoic acid is the strongest carboxylic acid is consistent with this. 

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