Dimethyl Sulfoxide → 3,6-Dimethyl-4,9-dihydro-3H-2,3,4,9-tetraaza-benzo[f]azulen-10-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Sodium (methylsulphinyl)methanide (22.7 mmol) was prepared from sodium hydride (60% dispersion in oil, 912 mg, 22.7 mmol) and anhydrous dimethyl sulphoxide (5.5 ml) by heating at 65° C. until a solution was observed. To this was added a solution of 5-(2-amino-4-methyl-phenylamino)-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester from Example E2.2 (3.56 g, 13.0 mmol) in anhydrous dimethyl sulphoxide (10 ml), and stirring continued at 65° C. for 30 min. The mixture was then poured into ice (200 ml), the resulting solid collected and purified by flash chromatography on silica gel (eluant; 10% methanol:90% dichloromethane) to yield the title compound (1.12 g, 38%).

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