4H-1,4-Benzothiazin-3-one → 2-[(4,5-Dimethylpyrrol-2-yl)methylene]-2H-1,4-benzothiazin-3(4H)-one

Participants

Reaction Conditions

Reaction Steps

4,5-Dimethylpyrrole-2-carboxaldehyde (0.27 g, 2.19 mmol) was added to a solution of 2H-1,4-benzothiazin-3(4H)-one (0.36 g, 2.19 mmol) and sodium methoxide (0.118 g, 2.19 mmol) in dry DMF (2 ml). The mixture was heated at 120° C. for 48 h, allowed to cool and poured into ice-water (50 ml). The precipitated solid was collected by filtration, washed with water, then dissolved in ethanol. The insoluble black residue was filtered out and the filtrate was concentrated to dryness under reduced pressure. The product was purified by silica gel chromatography using (98:2) dichloromethane:methanol as the mobile phase.

Provenance & Evidence