| 摘要 |
New cpds. are of formula (I), with their racemic mixts. of the cis and trans-isomers and their optical isomers. (where R1 is H or 1-4C alkyl; R2 is H, OH, 1-4C alkyl, 3-4C alkenyl, 3-4C alkynyl or 1-4C alkoxy; R3 is 1-4C alkyl, 3-4C alkenyl, 3-4C alkynyl, 1-6C alkanoyl, 1-6C halogen substd. alkanoyl, or mono- or disubstd. benzyl or benzoyl; and the mono- or disubstits. are methyl, methoxy, Cl, NO2 or 2,4- or 3,4-dichloro). Animal feedstuffs contain 0.0001-0.08 wt. % (I) and feed premixes contain 1-30 wt. % (I). (I) are useful as growth promoting agents for poultry or fur bearing and farm animals, and improve the feed conversion of the animals. They may be given in the feed or as implants. (I) are also herbicides useful for pre- or post-emergence control of broadleaf and grassy weeds, e.g. at 0.15-11.2kg/ha. A typical cpd., 4,5,6,7-tetrahydro-7-acetoxybenzo(b)thien-4-yl urea, is prepd. in 72% yield from 4,5,6,7-tetrahydro-7-hydroxybenzo(b)thien-4-yl urea and acetic anhydride in presence of pyridine. |
