反应详情

To a mixture of 51.0 g of the 3-cyano-4-[4-(2-methoxyethoxy)-5-sulfophenylazo]-1-phenyl-5-pyrazolone, 250 ml of acetone and 50 ml of phosphorus oxychloride was dropwise added 50 ml of N,N-dimethylacetamide at 50° C. or below. After the addition, the reaction mixture was stirred for about 1 hour and gradually poured into 1.0 l of ice water. The crystals precipitated were collected by filtration, washed with 100 ml of acetonitrile and dried by air. Thus, 46.7 g of 3-cyano-4-[4-(2-methoxyethoxy)-5-chlorosulfonylphenylazo]-1-phenyl-5-pyrazolone was obtained.

1. customat 50° C. or below
2. additionAfter the addition
3. customThe crystals precipitated
4. filtrationwere collected by filtration
5. washwashed with 100 ml of acetonitrile
6. customdried by air