  Mid infrared integrated quantum photonics is a promising platform for
applications in sensing and metrology. However, there are only few examples of
on-chip single photon sources at these wavelengths. These have limited
performances with respect to their C-band counterparts. In this work, we
demonstrate a new approach to generate heralded single photons in the mid
infrared on a silicon chip. By using a standard C-band pump, the inter-modal
spontaneous four wave mixing enables the generation of the herald idler at
1259.7 nm and the heralded signal at 2015 nm. The idler photon is easily
detected with a common infrared single photon detector while the signal photon
is upconverted to the visible before its detection. In this way, we are able to
operate a mid infrared source without the need of mid infrared detectors and
laser sources. By measuring a heralded $g^{(2)}$ of $0.23 \, \pm \, 0.08$ we
demonstrate the single photon behaviour of the source as well as the
feasibility of multi-photon coincidence measurements beyond 2 $\mu$m with our
setup. The source exhibits a high intrinsic heralding efficiency of $(59 \, \pm
\,5)\%$, a maximum coincidence to accidental ratio of $40.4 \, \pm \, 0.9$ and
a generation probability of $\left( 0.72 \, \pm \, 0.10 \right)$ W$^{-2}$.
