Moscow to Dubai is about 2,000 nautical miles and roughly five hours non-stop, within range of a midsize aircraft and everything above it. On this route the aircraft is the easy part; which operators may legally fly it is the question that has to be answered first.
Private jet charter from Moscow to Dubai starts from $30,500 on the smallest suitable aircraft. That is an indicative starting price, not a quote: the figure for your trip depends on which aircraft are available, where they are positioned and the date you fly.