3-アミノベンゼンスルホン酸

解説m-アミノベンゼンスルホン酸：メタニル酸ともいう．ニトロベンゼンをスルホン化後，還元すると得られる．無色の針状晶．融解せずに分解する．水に可溶，エタノールに難溶．解離定数K 2.0×10－4(25 ℃)．水酸化カリウムと溶融するとレソルシノールになる．アゾ染料の中間体である．

用途メタニルエローをはじめアゾ染料、顔料の中間体として広く使われる。

用途アゾ染料?蛍光染料中間体

使用Metanilic acid was used in the synthesis of cytocompatible sulfonated polyanilines. It was used in fabrication of novel glucose biosensor having large active surface area and excellent conductivity. It undergoes microbial desulfonation to 3-aminophenol by Pseudomonas sp. strain S-313. It can be used to produce CN3O6(1-)*Cs(1+) and dicesium salt of N-nitrometanilic acid at temperature of 25°C.

一般的な説明White powder. Small colorless needles; toxic.

Metanilic acid can be obtained by sulfonation of aniline sulfate with oleum and boric acid at 20 – 50 ℃. The yield is 98%. For industrial production, however, nitrobenzene is sulfonated to m-nitrobenzenesulfonic acid, which is then reduced either with iron or catalytically with hydrogen. Crude 3-aminobenzenesulfonic acid can be used directly, either as a solution or dried, to obtain 3-aminophenol by alkali fusion. It is not sufficiently pure for use in dye manufacture, however. Therefore the crude solution is acidified; after filtration the product thus obtained is of satisfactory purity.

純化方法Crystallise the acid from water (as the hydrate), under CO2 in a semi-darkened room. The solution is photosensitive. Dry it over 90% H2SO4 in a vacuum desiccator. [Beilstein 14 H 688, 14 IV 2640.]