7-(4,6-Dimethoxypyrimidinyl)oxy- and -thiophthalides as novel herbicides : Part 1. CGA 279 233 : a new grass-killer for rice

A series of novel types of 7-(4,6-dimethoxypyrimidin-2-yl)oxy - and -thio-3-methyl-1 (3H)-isobenzofuranones were discovered at Dr R Maag AG. From the thio-isobenzofuranyl series, CGA 279 233—BSI-proposed common name pyriftalid—was chosen for further development as a grass herbicide for use in rice. General synthetic approaches to these new phthalic acid-derived compounds are given, with emphasis on the synthesis of pyriftalid and its physico-chemical behaviour. © 2001 Society of Chemical Industry