PURPOSE: To provide novel compounds useful as excellent stabilizers for organic materials susceptible to oxidative, thermal or light-induced degradation such as lubricants, hydraulic liquids and natural or (semi)synthetic polymers.
CONSTITUTION: 3-Arylbenzofuranones are represented by formula I (wherein (n) is 1 or 2; R1 is naphthyl, phenanthryl or the like when (n) is 1 or phenylene, naphthylene or the like when (n) is 2; R2-R5 are each H, Cl or the like; and R6 is H or a group of formula II) and include, e.g. 5,3-di-tert-butyl-3-(2,5- dimethylphenyl)-3H-benzofuran-2-one. These compounds are preferably obtained by a novel method comprising reacting a compound of formula III with a compound of the formula: [H]n-R1 in the presence of a catalyst such as p- toluenesulfonic acid at a temperature of 70°C to the boiling temperature of the compound of the formula: [H]n-R1. Further, the compound of formula III is suitably obtained by reacting one equivalent amount phenol with 0.8-1.2 equivalent amount glyoxylic acid.
SAMIYUERU EBANZU
KURISUTOFU KUROONKE
YUNGU TSUINGU
