Tiron synthesis

Yield:149-45-1 73%

Reaction Conditions:

Stage #1:benzene-1,2-diol with sulfuric acid at 95; for 5 h;
Stage #2: with sodium hydroxide in water at 50;Product distribution / selectivity;

Steps:

1
Example 1: Sulfonation of Catechol in Concentrated H₂S0₄ The sulfonation of catechol derived from biomass using concentrated sulfuric acid was followed as described in Example A with minor modifications. Into a 1 L RBF containing 682 g of concentrated (98%) sulfuric acid, was added 150 g of catechol at RT. The mixture was heated at 95°C for 5h. When the reaction mixture was cooled to 50°C, 232 g of 47% (by weight) NaOH solution in water was added dropwise via an addition funnel to the reaction mixture to precipitate l,2-dihydroxy-3,5- benzenedisulfonate sodium salt. Upon complete addition of NaOH solution, the reaction was cooled to 15-25°C and the precipitate was filtered through a Biichner funnel. The solid was washed with isopropanol (600 mL) and dried under vacuum at 60°C to yield 312 g (73% yield) of l,2-dihydroxy-3,5-benzenedisulfonate sodium salt as an off-white solid.

References:

DRATHS CORPORATION;FROST, John, W.;BUI, Vu WO2011/22588, 2011, A1 Location in patent:Page/Page column 8

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