反应详情

50 ml of N,N-dimethylacetamide was added dropwise at 50° C. or lower to a mixture of 51.0 g of 3-cyano-4-[4-(2-methoxyethoxy)-5-sulfophenylazo]-1-phenyl-5-pyrazolone prepared as described in Step (a) of Reference Synthesis Example 1 above, and then 250 ml of acetone and 50 ml of phosphorous oxychloride was added. After completion of the dropwise addition, the reaction mixture was stirred for about 1 hour, and was then gradually poured into 1.0 l of ice water. The crystals thus-precipitated were recovered by filtration, washed with 100 ml of acetonitrile and air-dried.

1. customprepared
2. additionwas added
3. additionAfter completion of the dropwise addition
4. customThe crystals thus-precipitated
5. filtrationwere recovered by filtration
6. washwashed with 100 ml of acetonitrile
7. customair-dried