2H-1-Benzopyran-2-carboxamide, N-[6-amino-1-(6-chloro-3-pyridinyl)-3-ethyl-1,2,3,4-tetrahydro-2,4-dioxo- 5-pyrimidinyl]-3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-