Preparation and Deprotection of Aldehyde Dimethylhydrazones

Abstract

Aldehydes were conveniently protected as dimethylhydrazones by stirring a mixture of the aldehyde, N,N‐dimethylhydrazine, anhydrous magnesium sulfate, and dichloromethane at room temperature. Azeotropic removal of water, formed during the course of the reaction, was not required because anhydrous magnesium sulfate functions as a water scavenger. Deprotection of aldehyde dimethylhydrazones was accomplished by stirring a mixture of the aldehyde dimethylhydrazone and aqueous glyoxylic acid at room temperature. The reaction time for the preparation and deprotection of aldehyde dimethylhydrazones varied with the structure of the aldehyde.

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Keywords:

• Aldehyde dimethylhydrazones
• aqueous glyoxylic acid
• deprotection
• N,N‐dimethylhydrazine
• prepartion

Acknowledgments

I thank David Weisleder for acquisition of NMR data and Robert J. Bartelt for helpful discussions.

Notes

The mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.