Hydrochloric Acid → 2,3-Dichloro-6-nitrobenzonitrile

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Reaction Steps

Under a nitrogen atomosphere, pyridine (42 ml, 0.52 mol) was spread evenly over a mixture of 2,3,4-trichloronitrobenzene (225 g, 1 mol) and cuprous cyanide (89.6 g, 1 mol). The mixture was heated to 100° and held at this temperature until it became stirrable. Then the stirred mixture was heated to 165° over 1.5 hours, and held at this temperature for 30 minutes. The dark mixture was allowed to cool, then concentrated HCl (500 ml) and toluene (250 ml) were added. The mixture was vigorously stirred for 1.5 hours. The layers were separated and the aqueous phase was extracted with toluene (3 × 250 ml). The combined toluene extracts were washed with concentrated HCl (3 × 250 ml), water (250 ml) and saturated aqueous NaCl (2 × 250 ml). The toluene solution was dried over Na2SO4, filtered and stripped to obtain 185 g (85%) of the title benzonitrole. The product was 87% pure and contained about 7% trichloronitrobenzene. Recrystallization from methanol (2.1 ml/g) gave a product of 99% purity.

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