Phosphoric Acid → HCID 136408875, compound

Participants

Reaction Conditions

Reaction Steps

To 10 ml of concentrated sulfuric acid, 1.5 g of sodium nitrite was added and the mixture was heated at 70° C. with stirring. After stirring for 30 minutes, the mixture was cooled to 0° C. and 20 ml of acetic acid and 6 ml of a 85% phosphoric acid were added thereto. Then 5.0 g of 1-amino-2,4-dimethanesulfonylbenzene was added at below 5° C. thereto and the mixture was stirred for 3 hours. After adding 40 ml of ice water, a solution containing 6.5 g of 2-(N-4-sulfoanilinocarbamoyl)-1-naphthol obtained in Step (1) of Synthesis Example 3 above dissolved in 20 ml of a 2% aqueous sodium hydroxide was added dropwise to the mixture and the mixture was stirred at below 5° C. for 1 hour. The crystals thus-precipitated were collected by filtration and washed with 50 ml of acetonitrile.

Provenance & Evidence