How is 2-Thiophenecarbohydrazide (CAS: 2361-27-5) typically synthesized?

2-Thiophenecarbohydrazide is typically synthesized by reacting thiophene-2-carboxaldehyde with hydrazine hydrate. This synthesis involves the condensation of the aldehyde with hydrazine followed by the removal of water to form the final product. The reaction is carried out in a suitable solvent such as acetic acid, and the yield is generally around 70-80%.