It depends on the construction material. If the building is unreinforced masonry, the doorframe is the strongest part of the wall (with respect to earthquakes). If it is not, it is no stronger or weaker than the rest of the wall. (See https://earthquake.usgs.gov/learn/topics/megaqk_facts_fantas...).

The most useful place to be in a major earthquake is anywhere where things are not going to swing into or fall onto you. Such as underneath a desk (assuming it's not a cheap construction that will buckle under any significant weight).