7-(4,6-dimethoxypyrimiclinyl)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 pyriftali d-was chosen for further development as a grass herbicide for use in rice. General synthetic approaches to these new phthalic acid-derived compounds a re given, with emphasis on the synthesis of pyriftalid and its physico-chem ical behaviour. (C) 2001 Society of Chemical Industry.