Abstract 4-(4-Hydroxyphenyl)-2-phenylamino-1, 8-naphthyridine was prepared via cyclisation of N-phenyl-N′-3-(4-hydroxyphenethen-1-yl) pyridin-2-ylthiourea in the presence of mercuric oxide. Derivatives of 4-methyl-2-aminoquinolines were prepared in a similar manner from 2-vinylphenylthioureas.
