Why did Socrates accept the death sentence?

Socrates was near the end of his life when executed. He knew that in his death he could accomplish more than what he could in exile. Socrates was in prison for awhile, and had friends whom had a plot to get him escaped. He denied it, because he was put in there because of the law and even though the law may be wrong he still had to obey it. Therefore, he did not try to defy them and escape.