Acetone → 2-Chloroquinoline-4-carbonyl azide

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Reaktionsschritte

2-Chloro-4-chlorocarbonylquinoline (0.5 g), prepared by standard methods from 2-chloroquinoline-4-carboxylic acid, was added to sodium azide in aqueous dioxan (2.1 ml 1:3) at 0° C. Acetone was then added and the mixture stirred for 16 h. Water (10 ml) was added, the precipitated solid collected by filtration and air dried to give 2-chloroquinoline-4-carbonyl azide (0.455 g). The azide (0.232 g) in toluene (10 ml) was warmed from room temperature to 75° C. and then heating continued for 1 h. After cooling to room temperature 6-amino-2-methylbenzoxazole (0.148 g) in dichloromethane (15 ml) containing 4-N,N-dimethylaminopyridine (20 mg) was added and the mixture stirred for 16 h. The precipitated solid was separated by filtration to give a solid (0.25 g). Column chromatography (silica gel, dichloromethane/methanol/ammonia mixtures) gave the title compound (0.072 g). 1H NMR δ: 5 2.60 (3H, s), 7.25 (1H, d, J=8.5 Hz), 7.61 (1H, d, J=8.5 Hz), 7.73 (1H, t, J=7.0 Hz), 7.84 (1H, t, J=6.7 Hz), 7.91 (1H, d, J=8.0 Hz), 8.05 (1H, s), 8.20 (1H, d, J=8.25 Hz), 8.28 (1H, s), 9.49 (1H, s), 9.61 (1H, s). m/z (API+): 353, 355(MH+).

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