According to U.S. Senate Foreign Relations Chairman Bob Corker, Qatar is requesting to buy as many as 73 Boeing F-15Es.
By Alert5 (Own work) [CC BY-SA 4.0], via Wikimedia Commons
It will be split into two tranches with 36 jets delivered in the first tranche. Boeing will take 42 months to deliver the warplanes.
Corker has joined his Senate colleague, Armed Services Chairman John McCain, in criticizing the Obama government for delaying the requests from Qatar and Kuwait.
Kuwait has also been waiting for two years for 28 Boeing Super Hornets.
I think the senator has got his facts mixed up. The Qataris have had a plan to buy 72 fighters, which would likely have been split between European and U.S. vendors. Part of that program is already in action (24 Rafales + 12 options).
http://www.reuters.com/article/france-qatar-rafale-idUSL5N0XR2QJ20150430
http://www.barrons.com/articles/dassault-aviation-looks-ready-to-cruise-1452318132
http://www.janes.com/article/51086/qatar-selects-rafale-fighter-aircraft
So, unless Qatar plans to double up on its (already radical) air force expansion plan, its unlikely that Boeing will sell anything more than 36-48 F-15Es.