Amines dealkylations, 2- ethyl chloroformate

Reductive C-N bond cleavage has been demonstrated in more complex systems using ethyl chloroformate as a solvent. Chlorination of corticosteroid cyclic ethers has been observed. Tertiary aliphatic and alicyclic amines can be dealkylated. Phenyl chloroformate, however, is usually regarded as the reagent of choice. In summary, deamination, demethylation, debenzylation, and deal-lylation of tertiary amines can all occur on treatment with ethyl chloroformate but the regioselectivities of these reactions are difficult to predict. ... 

Alkyl esters are efficiently dealkylated to trimethylsilyl esters with high concentrations of iodotrimethylsilane either in chloroform or sulfolane solutions at 25-80° or without solvent at 100-110°.Hydrolysis of the trimethylsilyl esters serves to release the carboxylic acid. Amines may be recovered from O-methyl, O-ethyl, and O-benzyl carbamates after reaction with iodotrimethylsilane in chloroform or sulfolane at 50—60° and subsequent methanolysis. The conversion of dimethyl, diethyl, and ethylene acetals and ketals to the parent aldehydes and ketones under aprotic conditions has been accomplished with this reagent. The reactions of alcohols (or the corresponding trimethylsilyl ethers) and aldehydes with iodotrimethylsilane give alkyl iodides and a-iodosilyl ethers,respectively. lodomethyl methyl ether is obtained from cleavage of dimethoxymethane with iodotrimethylsilane. 

Olofson and coworkers also introduced vinyl chloroformate as a reagent for the N-dealkylation of tertiary amines (Ref. 157,158,159). Compared with commonly utilized reagents in N-dealkylation procedures, the use of VOC-CI leads to significantly improved yields under milder conditions combined with greater discrimination between alkyl groups in unsymmetrical amines. The procedure is illustrated by the selective N-deethylation of N-ethyl piperidine to afford piperidine.HCI in 90% yield (Ref. 159) as depicted in scheme 107. 

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