Yearly income around 280,000 - 340,000 DKK after taxes.
First time as unemployed in DK.
Am I eligible for "dagpenge"?
I assume that you are an EU-citizen or in other ways have the nessasary residence and work permit also after you will be unemployed from january 2018.
The requirements for being eligible for benefits are:
After what you tell us, It seems for me that you have no problem with meeting these two requirements.
Therefor you should be eligible for "dagpenge".
Remember to tell your A-kasse when your are unemployed, and apply for benefits. Also you must register as unemployed at www.Jobnet.dk. To be able to receive benefits you must actively search for new jobs, and be willing to take new job with 1 days notice.