ARS | Publication request: Preparation and Deprotection of Aldehyde Dimethylhydrazones

Submitted to: American Chemical Society Abstracts
Publication Acceptance Date: May 20, 2004
Publication Date: August 2, 2004
Citation: Petroski, R.J. 2004. Preparation And Deprotection Of Aldehyde Dimethylhydrazones [abstract]. American Chemical Society. Division Of Agricultural And Food Chemistry. Paper No. 84.

Technical Abstract: Aldehydes were conveniently protected as dimethylhydrazones by stirring a mixture of the aldehyde (1 mmol), N,N-dimethylhydrazine (1.3 mmol), anhydrous magnesium sulfate (2 mmol), and dichloromethane (3 mL) 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 was accomplished by stirring a solution containing the aldehyde dimethylhydrazone (0.1 mmol), acetone (1.5 mL), and aqueous cupric chloride (1.5 mmol in 1 mL water) at room temperature. Acetone was found to be a better reaction solvent than THF for the deprotection of unsaturated aldehydes because the formation of side products was suppressed. The reaction time for the formation and deprotection of aldehyde dimethylhydrazones varied with the structure of the aldehyde.