[imrober]

Hi,

I'm not sure of the equation you'd need, but I can say that the main idea behind Le Chatelier's principle is that:

A change in any of the main components that are involved in establishing an equilibrium (such as everything in solution) will cause the equilibrium to shift in order to counteract the change.

So if something (like the mononitrile substituted ring) is leaving the solution, the equilibrium of the reaction will shift to produce MORE of the precipitating product.

Hope that helps,

IR