Ultrasonic and Microwave-Assisted Synthesis of β-Nitro Styrenes and Nitro Phenols with Tertiary Butyl Nitrite under Acid-Free Conditions

Abstract

Tertiary butyl nitrite (TBN) is an acid-free and safe nitrating agent that provides preferentially β-nitrostyrenes with cinnamic acids and corresponding nitro derivatives with phenols in good yields under classical conditions. However, ultrasonic and microwave-assisted reactions reduced the reaction times substantially and enhanced the yields from good to excellent.

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GRAPHICAL ABSTRACT

Keywords:

• Microwave irradiation
• nitration of phenols
• nitrodecarboxylation of α,β-unsaturated acids
• sonication
• tertiary butyl nitrite (TBN)

ACKNOWLEDGMENTS

The authors are indebted to Professor P. K. Saiprakash (former dean, Faculty of Science, O.U.), Professor T. Navaneeth Rao (former vice-chancellor, O.U.), principal, Nizam College, and Head, Department of Chemistry, O.U.) for constant encouragement and facilities.

Notes

^a Reaction times: 2–4 h (conventional method); 45–60 min (sonication); 4–5 min (MWAR).

Notes. Reaction times: 1–3 h (conventional method), 30–45 min (sonication), 2–4 min (MWAR). M, major product; m, minor product.

^a Boiling point of liquids.