He planned to take over Germany ever since the Beer Hall putsch of 1923, if not earlier. The decision to kill the Jews is outlined in Mein Kampf (published 1925-6) and became official policy at the Wansee conference of January 1942.
He wanted to control germany because he wanted to free germany and the world from Jews and Communism
he thiught the Jews control everything at that time and it hurt germany
Hitler used the Jews as a SCAPEGOAT for Germany's problems.
Hitler decided to gas the Jews in nazi Germany
Hitler felt like the Jews poisoned society. He thought they were to blame for everything bad that happened in Germany like the economic crisis at the time and losing World War I.
It looks like there's a word missing in the question. Hitler certainly did not want Jews in Germany.
Germany has the best economy in Europe. Has the most outcome and budget cutbacks. Germany is the best because Hitler could control the economy and kill Jews with his brain.
The Jews
1941
Jews in Germany
Jews
Germany was in a hard economic crisis. Hitler was the solution. Hitler blamed the Jews for owning all bussinesses and not keeping money in Germany.