4-Arsabenzaldehyde

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. 

Arsabenzaldehydes appear to be normal aromatic aldehydes26 37115. 4-Arsa-benzaldehyde (36) undergoes the Aldol and Knoevenagel as well as a variety of typical aldehyde addition reactions 37,115). 

Investigations continue into the chemistry of arsabenzenes bearing common functional groups. For example, Wittig reactions on arsabenzaldehyde (186 X = 0), although slow (30 h), give the 4-vinyl derivatives (186 X = CHCOR R = Me, Ph, or OMe) in practicable yields. Attack by a carbanion at arsenic is not observed. 

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