Analytic Approximations of 2 2 Processes with Massive Internal Particles

We consider two-loop corrections to 2 -> 2 scattering processes with massive particles in the final state and massive particles in the loop. We discuss the combination of analytic expansions in the high-energy limit and for small Mandelstam variable t. For the example of double Higgs boson production we show that the whole phase space can be covered and time-consuming numerical integrations can be avoided.