A cyclic amidine typically having the formula: ##STR1## wherein R.sup.1 represents an organic radical, X represents a direct bond or a divalent organic radical and A and B each represent hydrogen or an organic radical is prepared by a liquid phase reaction of a nitrile of the formula R.sup.1 CN where R.sup.1 has the same meaning as above, with a polyamine typically having the formula: ##STR2## where X, A and B have the same meaning as above, in the presence presence of a mixture of a titanium compound with water.