Both N-methylmorpholine and triethylamine are basic. They are both tertiary amines, which means they have three alkyl groups attached to the nitrogen atom. The nitrogen atom in the tertiary amine has a lone pair of electrons, which can donate to the proton, making the amine basic.
The basicity of a tertiary amine depends on the number of alkyl groups attached to the nitrogen atom. The more alkyl groups attached, the less basic the amine is. This is because the alkyl group sterically blocks the lone pair of electrons on the nitrogen atom, making it more difficult for the nitrogen atom to donate the lone pair of electrons to the proton.
N-methylmorpholine has a pKa of 7.4 and triethylamine has a pKa of 10.5. This means that N-methylmorpholine is a weaker base than triethylamine. This is because there are two alkyl groups on the nitrogen atom of N-methylmorpholine, while there is only one alkyl group on the nitrogen atom of triethylamine. The two alkyl groups on N-methylmorpholine sterically hinder the lone pair of electrons on the nitrogen atom, making it more difficult for the nitrogen atom to donate the lone pair of electrons to the proton.
N-methylmorpholine and triethylamine are both used as bases in a variety of applications, including:
As a catalyst for organic reactions
As a pH buffer
As a corrosion inhibitor
As a flotation agent
N-Methylmorpholine is also used as a solvent for organic compounds.
