Water → HCID 68182943, compound

Participants

Reaction Conditions

Reaction Steps

In a 250-ml round bottomed flask equipped with a stirbar was placed 4-(3,4-dichlorophenyl)-N-hydroxy-5,6-dihydro-1-benzothiophen-7(4H)-imine (1.25 g, 4.00 mmol) and polyphosphoric acid (40 g, 200 mmol). The resulting mixture was heated at 130° C. under an atmosphere of nitrogen with stirring for ˜4 hours, leaving a dark brown mixture. The mixture was allowed to cool to rt then water and ethyl acetate were added. The mixture was stirred briefly then transferred to a separatory funnel. The organic layer was separated then the aqueous layer was extracted with additional ethyl acetate. The organic layers were combined, washed with brine, dried over sodium sulfate, filtered, and evaporated to leave crude product as a brown oil. The residue was purified using column chromatography on silica gel (120 g RediSep column, gradient 0% ethyl acetate in dichloromethane to 90% ethyl acetate in dichloromethane over 20 minutes) give the product 1.08 g (86% yield) product as a light tan solid. LCMS: (FA) ES+ 312, 314. 1H NMR (400 MHz, DMSO) δ 8.24-8.12 (s, 1H), 7.65-7.59 (d, J=5.2 Hz, 1H), 7.60-7.51 (d, J=8.3 Hz, 1H), 7.45-7.36 (d, J=2.1 Hz, 1H), 7.11-7.01 (dd, J=8.3, 2.1 Hz, 1H), 6.64-6.51 (d, J=5.2 Hz, 1H), 4.56-4.42 (dd, J=8.8, 5.5 Hz, 1H), 3.25-3.03 (m, 2H), 2.34-2.18 (m, 1H), 2.10-1.95 (m, 1H).

Provenance & Evidence