Compounds of the formula (I), in which Het, R, X, Y, R
1
and p have the meanings indicated in claim
1
, are autotaxin inhibitors and can be employed for the treatment of tumours.
Compounds of the formula (I), in which Het, R, X, Y, R1 and p have the meanings indicated in claim 1, are autotaxin inhibitors and can be employed for the treatment of tumors.