  We consider the case of a two-loop five-point pentagon-box integral
configuration with one internal massive propagator that contributes to
top-quark pair production in association with a jet at hadron colliders. We
construct the system of differential equations for all the master integrals in
a canonical form where the analytic form is reconstructed from numerical
evaluations over finite fields. We find that the system can be represented as a
sum of d-logarithmic forms using an alphabet of 71 letters. Using high
precision boundary values obtained via the auxiliary mass flow method, a
numerical solution to the master integrals is provided using generalised power
series expansions.
