Methyl propiolate → ethyl 2-oxo-2H-pyrimido[2,1-b]benzothiazole-8-acetate

Beteiligte Stoffe

Reaktionsschritte

A stirred mixture of 5 g of ethyl 2-aminobenzothiazole-6-acetate [prepared according to Sawhney et al., Ind J. Chem., Vol. 16B p. 605 (1978)], 1.95 g of methyl propiolate and 30 ml of ethanol was heated under reflux for 2 hours and the mixture was allowed to cool. The crude product was collected and then recrystallized from n-butyl alcohol to obtain 2.88 g of ethyl 2-oxo-2H-pyrimido[2,1-b]benzothiazole-8-acetate as yellow needles (48% yield).

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