To obtain the subject compound useful for a herbicide, having no phytotoxicity to cultivated plants, capable of destroying various kinds of weeds once with a small amount, by converting a carbon atom at the 4-position of a thiochroman into a heteroatom.

This compound is shown by formula I [R1 is a 1-4C alkyl, a 2-4C alkenyl or a 2-4C haloalkenyl; R2 is H, a 1-4C alkyl or a 1-4C haloalkenyl; X is a 1-4C alkyl, a 1-4C haloalkyl, a 2-4C alkoxyalkyl, etc.; (p) is 0 or 1-3; Z is O, SOr ((r) is 0, 1 or 2), etc.; Q is H, A-B (A is a group of formula II, etc.; B is a 1-12C alkyl, a 3-10C cycloalkyl, etc.; D is a 1-3C (un) saturated alkylene; Y is oxo, a 1-4C alkyl, etc.; (m) is 0-6; (n) is 0, 1 or 2) such as 6,9-dimethyl-7-(1'-ethyl-5'-hydroxypyrazol-4'-yl)carbonyl-1,5-benzothiazepin-4-one. The compound is obtained, for example, by subjecting a compound of formula III and a compound of formula IV to ester condensation.