C₆H₇NO₃S(sulfanilic acid)

Synthesis of methyl orange, The

and The relationship with each color

Synthesis of methyl orange, The

and The relationship with each color

IntroductionAkira Suzuki was awarded a Nobel prize in 2010. Mr. Suzuki’s experiment is called Suzuki

a key of the study called the organic synthetic study. It used lots of fields. Above all, medicine is necessary for doctors which I want to

become to treat diseases. Thus, I wanted to do an experiment like this experiment in

coupling reaction in my experiment. Furthermore, I focusd on Methyl orange. Methyl

Finally, I made up my experiment purpose as follows.

①Synthesis and creation of methyl orange

②Find a relation between pH change and color of methyl orange which is influenced by the strength of the

�Color : reddish orange

�Structural formulaConstruction form↑

C₈H₁₁N（dimethyl aniline) 3mlNaOHaq (1mol/L) NaCl 25gH₂O

Synthesis and creation of methyl orange �preparation

Week Week acid

yellow

strength

Something to want to analyze Something to want to analyze

red

Construction of methyl orange

Na₂CO₃ 2g NaNO₂ 1.8gNaOHaq (1mol/L) NaCl 25gH₂O

125ml HCｌaq 60ml（3mol/L)

�Method of synthesis

C₆H₇NO₃S (white)

C₈H₁₁N （white)

←Sulfanilic acid and

dimethyl aniline to

make Methyl orange.

Adjustment of sulfanilic acid

color： reddish brown

Adjustment of sulfanilic acid①Dissolve sulfanilic acid into a mixture

of water and sodium carbonate, and heat the mixture.

color：transparent and colorless②Add sodium nitrite allowing the

mixture to get cool and after that, add a mixture of hydrochloric acid and water.

color： reddish brown

Adjustment of dimethyl aniline

color：transparent and colorless

Adjustment of dimethyl aniline①Mix dimethyl aniline and hydrochloric acid in another beaker, and cool the mixture.

color：transparent and colorless

�Method

①mixed these two materials.color：dark red

②controlled the pH by adding sodium hydroxide. color：orange

③Precipitation occured by adding sodium chloride.④Performed a vacuum filtration.

�Product

I was able to make methyl orange I was able to make methyl orange I was able to make methyl orange I was able to make methyl orange 0.8g0.8g0.8g0.8g from from from from 8.0g8.0g8.0g8.0g materials.materials.materials.materials.

（（（（Collection rateCollection rateCollection rateCollection rate 10101010％）％）％）％）

www.aichi-c.ed.jp/contents/rika/koutou/kagaku/ka3/metir/metir.htmwww.aichi-c.ed.jp/contents/rika/koutou/kagaku/ka3/metir/metir.htm

�Results

The percentage of permeation of each color influenced by

aqueous

conclusion

・I made methyl orange by

・optical

1）江藤康文 色

3）東京工業大学化学実験室

4）愛知エースネット

6）科学技術コミュニケーション教育研究部門（科学技術コミュニケーション教育研究部門（科学技術コミュニケーション教育研究部門（科学技術コミュニケーション教育研究部門（

References

The strength of acid,

The relationship with each color

The strength of acid,

The relationship with each color

Nobel prize in 2010. Mr. Suzuki’s experiment is called Suzuki-Miyaura Coupling. This experiment becomes

It used lots of fields. Above all, medicine is necessary for doctors which I want to

an experiment like this experiment in my school science laboratory ,so I used the Diazo

on Methyl orange. Methyl orange which is used as a dye and indicator.

Find a relation between pH change and color of methyl orange which is influenced by the strength of the acid

試験管の写真

Week Week acid

yellow

Strong Strong acid red

strength of acid and relation with methyl orange color

Something to want to analyze Something to want to analyze

White light � Control pH

波長は 440 ～ 680 nm

Check performance by coloration of methyl orange I made.

�Analyze optical properties by using an absorptiometer

Analyze like this way→

Inner figure

White light � Control pH pure hydrochloric acid pH２（red）controlled hydrochloric acid pH5（yellow）

Results

The percentage of permeation of each color influenced by

aqueous solution.

The opposite color is absorbed based on the color

that we recognize.

conclusion

I made methyl orange by diazo coupling.

acidity neutrality basicity

optical property …I made a graph of color changes according to differences of pH.

その科学と文化 朝倉書店 1979 2）L.F.フィーザー フィーザー有機化学実験 丸善 1980

）東京工業大学化学実験室 理工系大学基礎化学実験第３版 講談社サイエンティフィク 2008

）愛知エースネット メチルオレンジの合成 5）Nobelprize.org – All about the Nobel Prize Awarded Achievements, http://nobelprize.org/,（（（（2011/02/22））））

科学技術コミュニケーション教育研究部門（科学技術コミュニケーション教育研究部門（科学技術コミュニケーション教育研究部門（科学技術コミュニケーション教育研究部門（CoSTEP）鈴木・宮浦カップリング反応とは）鈴木・宮浦カップリング反応とは）鈴木・宮浦カップリング反応とは）鈴木・宮浦カップリング反応とは http://costep.hucc.hokudai.ac.jp/channel/anime/index.html

References

red yellow