The invention concerns quinazoline derivatives of Formula (I) wherein each of Q.sup.1, Z, R.sup.1 and Q.sup.2 have any of the meanings defined in the description; processes for their preparation, pharmaceutical compositions containing them and their use in the manufacture of a medicament for use as an antiproliferative agent in the prevention or treatment of tumours which are sensitive to inhibition of erbB receptor tyrosine kinases. ##STR00001##