1968 Volume 26 Issue 6 Pages 490-493
Upon treatment of dimethyl terephthalate with methylsulfinylcarbanion in DMSO, a solution of the carbanion of 1, 4-bis(methylsulfinyl acetyl) benzene (2) was obtained. When the solution was treated with an aqueous acid, compound (2) underwent Pummerer rearrangement to yield p-phenylenediglyoxal bis(methylhemimercaptal) (8), which gave p-phenylenediglyoxal (9) on hydrolysis. p-Phenylenediglycolic acid (10) was also prepared from (8). Reduction of (2) with zinc dust and acetic acid gave p-diacetylbenzene (3) and this was converted to a bisepoxy compound, 1, 4-bis(1', 2'-epoxyisopropyl) benzene (7), by the action of a sulfonium methylide. The bis-(Mannich base), 1, 4-bis (β-N, N-dirnethylaminopropionyl) benzene dihydrochloride (5) derived from (3), formaldehyde, and dimethylamine hydrochloride gave a bispyrazoline by condensation with phenylhydrazine.