Isobutyryl hydrazine can be used as a pharmaceutical synthesis intermediate. Examples of its applications are as follows:
1) Preparation of 3-isopropyl-4-amino-1,2,4-triazolin-5-one, comprising: Step 1, reacting isobutyric acid and hydrazine hydrate in n-butanol solvent at a reaction temperature of 50–150°C to generate isobutyryl hydrazine; Step 2, reacting the isobutyryl hydrazine reaction solution synthesized in Step 1 with phosgene or solid-phase phosgene and n-butanol as a solvent at a reaction temperature of 0–60°C to generate butyl 2-isobutylhydrazine carbamate; Step 3, reacting the butyl 2-isobutylhydrazine carbamate synthesized in Step 2 with hydrazine hydrate in an alkaline solution at a reaction temperature of 80–120°C to generate 3-isopropyl-4-amino-1,2,4-triazolin-5-one and n-butanol. This invention uses n-butanol as the solvent throughout the entire reaction process, without separation in the intermediate steps. It boasts advantages such as a simple reaction system, fast reaction rate, low waste volume, reusable n-butanol, and a high yield of up to 85%.
2) Preparation of a new class of indole derivatives. Using derivatives of indole-3-carboxaldehyde and isobutyrylhydrazine as raw materials, anticancer active groups such as -OCH3 and -C=N-NH-C=O are introduced, either wholly or partially, into appropriate positions of indole through chemical reactions to obtain a series of indole compounds containing multiple functional groups. This process is simple to operate, has mild reaction conditions, and high yield. Furthermore, these compounds exhibit good biological activity and can be used to treat tumors, showing broad application prospects in the pharmaceutical field.
[1] Medicinal Chemistry, 2013, vol. 9, # 7, p. 968 - 973
[2] Patent: WO2016/127859, 2016, A1. Location in patent: Paragraph 00233
[3] Journal fuer Praktische Chemie (Leipzig), 1930, vol. <2>125, p. 176
[4] Journal fuer Praktische Chemie (Leipzig), 1904, vol. <2>69, p. 498
[5] European Journal of Medicinal Chemistry, 1990, vol. 25, # 1, p. 75 - 79
