Including 2,6-dichlorobenzamide was prepared as follows: in a 500 ml reaction flask, add 2,6-dichlorobenzonitrile 51.6 g (0.3 mol), 41.6 g of water, 0.6 g of 30% sodium hydroxide solution, warming to 35 C., drop 55.65 g (0.45 mol) of 27.5% hydrogen peroxide, 5 hours to drop, drop after the completion of the sampling of the center control, 2, 6 -Dichlorobenzonitrile≤0.5% qualified. Filtration, the filter cake with 83.2g water rinsing, wet product drying to get the finished product 2,6-dichlorobenzamide 55g, purity >99.0%, yield 97%.
Oral doses of DCB are excreted by rats as DCB, two
monohydroxy-DCBs, 2-chloro-5-hydroxy-6-
(methylthio)benzamide, and 2-chloro-5-hydroxy-6-[S-
(N-acetyl)-cysteinyl]benzamide. Biliary excretion (33%
of the dose), enterohepatic circulation, and intestinal
microfloral metabolism are involved in the formation of
2-chloro-5-hydroxy-6-(methylthio)benzamide. The
major route for the metabolism of DCB is the
conjugation with glutathione in a process involving
phenyl ring hydroxylation at the ortho position to the
S-glutathionyl moiety. Two mechanisms can be
processed for the formation of hydroxylated
metabolites resulting from the epoxidation at the 2-
and 3-positions of the phenyl ring (for the proposed
mechanisms: see the text).
