Regioselective Synthesis of Pyrazoles from β-Oxo Thioxoesters and α-Oxoketene O,N-Acetals

Significance

A regioselective synthesis of pyrazoles under identical solid support and ultrasound conditions is reported. However, the regioselecti­vity is a function of β-oxo thioxoester A and α -oxo­ketene O,N-acetal B starting materials perhaps owing to higher electrophilicity of thioester and oxo­ketene acetal carbonyl, respectively. The scope of the reaction was not adequately investigated.