Background: Recently, we developed a rapid procedure for the Leuckart reaction and successfully applied it for the synthesis of substituted N-benzyl-N-methylformamides. Interestingly, in the reaction conducted on 2-chlorobenzaldehyde, a large amount of a by-product, N,N-di-(2-chlorobenzyl)-N-methylamine was produced with an isolated yield of 42.5%. N-(2-chlorobenzyl)-N-methylformamide was produced with an isolated yield of 37.3%. The ratio of the yield of the dibenzyl product to the yield of the monobenzyl product was 1.14:1. Hypothesis: The reaction conducted on benzaldehydes with electron-donating substituents may produce higher yields of the respective N,N-dibenzyl-N-methylamines and lower yields of the respective N-benzyl-N-methylformamides. In this work the hypothesis was tested by conducting the reaction on 2-methoxybenzaldehyde. Methods: The reaction was conducted on 10 mmol scale at 186-190°C. Column chromatography was used for the isolation of the products. NMR-spectroscopy and elemental analysis were used to determine the structures of the products. Results: The reaction was completed in 10 minutes. The isolated yield of N-(2-methoxybenzyl)-N-methylformamide (34.6%) was similar to the yield of N-(2-chlorobenzyl)-N-methylformamide in the previous reaction. However, the isolated yields of N,N-di-(2-methoxybenzyl)-N-methylamine (64.9%) was 22.4% higher than the yield of N,N-di-(2-chlorobenzyl)-N-methylamine. The ratio of the yield of the dibenzyl product to the yield of the monobenzyl product shifted to 1.88:1. Conclusions: The results of the reaction support the initial hypothesis. The reaction provides a new method for the synthesis of N-(2-methoxybenzyl)-N-methylformamide and N,N-di-(2-methoxybenzyl)-N-methylamine. Both products of the reaction are new compounds.

Rapid synthesis of N,N-di-(2-methoxybenzyl)-N-methylamine

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.