Abstract: 7-hydroxy-4-methyl coumarin as chemical or medical intermediates is very important in industry.The synthesis of 7-hydroxy-4-methyl coumarin was studied using activated carbon supported phosphotungstic acid as catalyst.The effects of various factors on the reaction were discussed in detail.The optimum conditions were obtained for industrialization.The molar ratio of resorcin to acetyl ethyl acetate was 1:1,reaction temperature is 100 ℃,reaction time is 3 h,the amount of loaded phosphotungsic acid is 22.3%,the catalyst dosage is 0.15 g.The yield reached 73.4%.

Key words: 7-hydroxy-4-methyl coumarin, activated carbon, phosphotungstic acid；synthesis