反应详情

温度

2.5 °C

To a mixture of N-[4-hydroxy-3-[2-methyl-1-(4-methylphenyl)-1-propenyl]-2,5,6-trimethylphenyl]formamide (740 g) and isobutanol (2220 ml) was added concentrated hydrochloric acid (2220 ml) under nitrogen stream and the mixture was refluxed under heating for 5 hr. The mixture was stirred at 0 to 5° C. for 1 hr. The crystals were collected by filtration and washed with toluene to give 2,2,4,6,7-pentamethyl-3-(4-methylphenyl)-2,3-dihydro-1-benzofuran-5-amine hydrochloride. This hydrochloride was dissolved in a mixed solution of methanol (5180 ml)/water (740 ml) at 55 to 60° C. To the solution was added dropwise 25% aqueous ammonium at 50° C. to adjust the pH to 8.5, and the mixture was stirred for 30 min. The precipitated crystals were collected by filtration and washed with methanol/water (1:1) to give the title compound (587.2 g, yield 87.4%).

1. temperaturethe mixture was refluxed
2. temperatureunder heating for 5 hr
3. filtrationThe crystals were collected by filtration
4. washwashed with toluene