Catalyst free cyclocondensation of β-ethylthio-β-indolyl-α, β-unsaturated ketones with hydrazines: Efficient synthesis of 3-pyrazolyl indoles

Abstract

Catalyst free cyclocondensation of β-ethylthio-β-indolyl-α,β-unsaturated ketones with hydrazines has been developed, and 3-pyrazolyl indoles were efficiently synthesized in excellent yields. The catalyst free protocol avoids the use of a large excess of catalysts such as acids and bases, eliminating the discharge of harmful chemicals.

Graphical Abstract

Keywords:

• Cyclocondensation
• β-ethylthio-β-indolyl-α
• β-unsaturated ketones
• hydrazines
• indole derivatives
• 3-pyrazolyl indoles

Additional information

Funding

Supported by the Foundation of Science and Technology Research Projects of the 13th Five-Year Plan of Jilin Provincial Department of Education [2016037].