Methanesulfonic Acid → HCID 10297662, compound

Participants

Reaction Steps

180.1 g (1.49 mol) of pivaloyl chloride are added dropwise over a period of 25 minutes to a suspension of 274.5 g (0.75 mol) of 3-(3,5-dimethyl-4-hydroxyphenyl)-5,7-di-tert-butylbenzofuran-2-one, (compound (107), Table 1, Example 2) in 600 ml of xylene and 7.5 ml (115.7 mmol) of methanesulfonic acid which is stirred at 95° C. under a nitrogen atmosphere. The clear, homogeneous reaction mixture is then refluxed for another 2.5 hours and then concentrated under a slight vacuum. 50 ml of 1-butanol and 600 ml of methanol are carefully poured into the liquid, hot residue at about 170° C. through the condenser and the mixture is cooled with ice/water. The precipitated product is filtered and washed with 350 ml of cold methanol. Drying gives 311.9 g (92%) of 3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one, melting point 140°-142° C. (compound (110 ), Table 1).

Provenance & Evidence