| 摘要 |
The invention relates to novel heterocyclic trichloromethyl derivatives, particularly 2-trichloromethyl-substituted quinazoline, benzo[d]-[1,3]-oxazine and benzo[e]-[1,3]-oxazine derivatives, for example 1,2-dihydro-2-trichloromethylquinazolin-4-one. The compounds of the invention are at least as effective as prior art trichloromethyl derivatives, which reduce the production of methane during the rumen metabolism of ruminant animals, and increase the formation of propionate at the expense of acetate, and hence improve the animals' rate of growth and their efficiency of food utilization. |
