preferred_name: ethene + chloride + A + H(+) => chloroethene + AH2
preferred_name_lc: ethene + chloride + a + h(+) => chloroethene + ah2
label: ethene + chloride + A + H(+) => chloroethene + AH2
label_lc: ethene + chloride + a + h(+) => chloroethene + ah2