Fuming sulfuric acid → HCID 10355651, compound
Reaction equation
[S:1]([C:5]1[C:14]2[C:9](=[CH:10][C:11]([C:15]([OH:17])=[O:16])=[CH:12][CH:13]=2)[CH:8]=[CH:7][C:6]=1N)([OH:4])(=[O:3])=[O:2].C1C(C(O)=O)=CC2C=CC([OH:27])=CC=2C=1.S(=O)(=O)(O)O.S(=O)(=O)=O.S(=O)(=O)=O>>[S:1]([C:5]1[C:14]2[C:9](=[CH:10][C:11]([C:15]([OH:17])=[O:16])=[CH:12][CH:13]=2)[CH:8]=[CH:7][C:6]=1[OH:27])([OH:4])(=[O:3])=[O:2]Participants
Procedure
The 1-sulfo-6-carboxy-2-aminonaphthalene starting compound has not been disclosed before. It can be prepared according to the present invention by first sulfonating 2-naphthol-6-carboxylic acid in a sulfuric acid/sulfur trioxide mixture (oleum) having a sulfur trioxide content of 0 to 65% by weight at a temperature between 0° C. and 40° C., preferably at 0° to 10° C., to 1-sulfo-6-carboxy-2-naphthol, isolating this compound and then reacting it at a temperature between 100° and 160° C. in an autoclave in aqueous medium with ammonium hydrogen-sulfite. The 1-sulfo-6-carboxy-2-naphthol is isolated from the reaction mixture in a conventional manner by carefully pouring the reaction batch onto ice. The precipitated product is filtered off with suction and suspended in ice-water, and any sulfuric acid still present is neutralized with sodium carbonate by adjusting the suspension to a pH between 4 and 4.5. The compound can then be isolated by filtering off with suction and drying.
Workup
- customIt can be prepared
- customat a temperature between 0° C. and 40° C.
Sources & evidence
- ORD record
- ord-30023da0cc6f4741a1cc4128280a6071
- Source dataset
- uspto-grants-1994_05
- Patent number
- US05310886
Reaction notes
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