In the aminal-type title compound, C(10)H(15)N(3), the six-membered hexa-hydro-pyrimidine ring adopts a chair conformation and the N atoms are pyramidally coordinated. One of the two amido -NH units engages in inter-molecular hydrogen bonding with the pyridyl N atom, generating a helical chain running along the b axis of the ortho-rhom-bic unit cell.