Transition Metal–Free Sodium Borohydride Promoted Controlled Hydration of Nitriles to Amides

Abstract

A transition metal–free process, promoted by sodium borohydride, has been developed for convenient and selective hydration of nitriles to corresponding amides. The present process converts the aromatic, aliphatic, and heteroaromatic nitriles with wide functional group tolerance. The regioselective hydration of one nitrile moiety in the presence of an other nitrile group makes high impact in the present protocol.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]

GRAPHICAL ABSTRACT

Keywords:

• Amide synthesis
• nitrile hydration
• sodium borohydride

ACKNOWLEDGMENTS

The authors are grateful to P. S. Ahuja, director of the institute, for providing the necessary facility and encouragement. P. K. V. and U. S. are thankful to the Council of Scientific and Industrial Research for a fellowship and V. K. is thankful to University Grants Commission for a fellowship.

Notes

^a Reaction conditions: 4-nitrobenzonitrile (1 mmol), NaBH₄ (0.1 to 25 equiv), EtOH–H₂O (1:1, 5 mL), 80 °C, 4 h.

^b GC-MS yield.

^c Reaction at room temperature.

^a Reaction conditions: nitrile (1 mmol), NaBH₄ (0.75 equiv), EtOH : H₂O (1:1, 5 mL), 80 °C.

^b GC-MS yield; isolated yields are given in parentheses.

^c 5 equiv of NaBH₄ was used.

^a Reaction conditions: nitrile (1 mmol), NaBH₄ (0.75 equiv), EtOH–H₂O (1:1, 5 mL), 80 °C.

^b GC-MS yield; isolated yields are given in parentheses.

^a Reaction conditions: nitrile (1 mmol), NaBH₄ (0.75 equiv), EtOH–H₂O (1:1, 5 mL), 80 °C.

^b GC-MS yield; isolated yields are given in parentheses.

IHBT Communication No. 2369.