Dear Incredible New,

The N-alkylation of 3,4-dihydroquinazoline can be conducted using alkylating agent such as alkyl halides (alkyl iodide) in the presence of triethylamine. The latter is used to capture the hydrogen halide released during the reaction.

This type of reaction proceeds at room temperature within few hours. You can monitor the reaction by TLC. The amount of alkyl halide should be used in excess. If you want to make alkylation of both nitrogens in 3,4 dihydroquinazoline you should use 3 equivalent or more.

Hoping this will be helpful,

Rafik

Thanks Mr.Rafik