1-Fluoro-2-nitrobenzene → HCID 14625404, compound

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A mixture of hexahydro-5-(phenylmethyl)-1H-1,2,5-triazepine dihydrochloride (35.0 g), 1-fluoro-2-nitrobenzene (21 ml), N,N-diisopropylethylamine (81 ml) in N,N-dimethylformamide (400 ml) was stirred and heated at 75°-80° (under reflux) under nitrogen for 5 hours. The solution was evaporated to a syrup under oil pump vacuum and the residue was mixed with chloroform and dilute sodium hydroxide. The aqueous phase was extracted several times with chloroform. The combined extracts were dried (MgSO4) and evaporated to a syrup wich was subjected to an oil pump vacuum. The syrup in toluene was applied to a column (94×8.7 cm) of dry column grade neutral alumina prepacked in toluene. Elution with toluene removed a faster moving yellow impurity. Fractions were monitored by t.l.c. on Alox-25 uv254 plates (Brinkmann) with chloroform as developer. As soon as the major component started to issue the eluting solvent was changed to toluene-chloroform (4:1), toluene-chloroform (1:1) and finally chloroform. Appropriate fractions were evaporated to a syrup which was crystallized from ether-heptane; wt. 35.7 g (86%), mp=90°-92°. Recrystallization from chloroform-ether-heptane gave pure titled product, mp=90°-92°.

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