Abstract: This invention relates to compounds of the general formula: in which the variable groups are as defined herein, and to their preparation and use.

Abstract: The locating pins have notched ends, each of which simultaneously restricts the movement of an expendable core in two orthogonal directions in a die casting die. A plurality of these pins alone and with other pins project into the space between the printout cavity in a die casting die and the printout portion of an expendable core positioned in that cavity. Other pins having flat ends locate the core in only one directional line. Still other pins having tapered ends require special pockets in the printout section of the core, which pockets have sides that must be formed adjacent to the tapered surfaces of these pins. The configurations of the space around the printout portions of the cores permit molten metal injected into the die to produce a skin or skull over the printout portions, which skin can have thicker ribs or portions through it for further reinforcing the printout portions.