The IUPAC name of (CH₃)₂NCH₂CH₃ is:
For tertiary amines, the largest alkyl group is the parent chain. Here, ethyl (CH₂CH₃) is the parent, with two methyl groups on nitrogen, named N,N-dimethylethanamine, as per the PDF.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Chemical Reactions - Carbylamine Reaction and General Reactions