Organik Kimya Temelleri
Organik Kimyanın Kısa Tarihi - Bilim Genç
Organik Kimyanın Kısa Tarihi ... İlk kimyacılar çoğunlukla canlılardan elde edildikleri için ısıtıldıklarında yanan ve sonra eski hâllerine ...
çalışıyordu
1856’da henüz 18 yaşındayken William Perkin ilk sentetik organik boyayı keşfetti. William Perkin kömür katranını kullanarak sıtma tedavisi için ihtiyaç duyulan kinin isimli maddeyi sentezlemeye <anchor>çalışıyordu</anchor>. Perkin, deneyleri sırasında kullandığı şişeyi alkolle temizlerken mor renkli bir çözelti elde etti. Bu çözelti ipek kumaşı boyadı ve kumaş yıkansa da mor renk kumaşta kaldı. Perkin geliştirdiği yöntemin patentini aldı.
William Henry Perkin
### William Henry Perkin (1838-1907)

The career of Sir William Henry Perkin was initiated by
one of the most fortuitous discoveries in the history of
chemistry. He did not realize his goal, but his curiosity
led to financial success.

Perkin was a student at the City of London Day School
where he was influenced by Mr. Thomas Hall, a former student
of Hofmann at the Royal College of Chemistry. In spite of Perkin senior's
desire for his son to become an architect [for an
architect turned chemist, see August  
Kekule], several meetings with Hall set the course
for Perkin's future career as a chemist.

Perkin entered the Royal College at the tender age of
fifteen in 1853. Because Perkin was otherwise engaged during
the day in research at the College, he set up a home
laboratory where he was able to conduct his own work in the
evening and during vacation. In 1849, Hofmann had suggested
how certain coal tar products could be converted into
alkaloids (base-like, i.e., amines). As a consequence, the
synthesis of the naturally occurring alkaloid, quinine, from
the bark of the cinchona tree was offered as a challenging
and worthwhile undertaking. During the Easter recess of
1856, young Perkin decided to synthesize quinine. [In
1856, there was no idea of how atoms were connected
(structure) nor agreement on the combining masses of atoms.
This challenge may have stimulated Perkin at this time
because England was engaged in the Crimean War (1854-1856).
The British Empire was undoubtedly a user of quinine to
combat malaria. Quinine was not synthesized until 1944 by
Doering and Woodward during World War II. The motivation for
the synthesis was to provide a source of quinine for the
manufacture of polarizers. ]

By simply balancing the masses of an equation, Perkin
thought that two allyltoluidines
(C10H12N) upon oxidation with three
oxygen atoms (potassium chromate) would give quinine
(C20H21N2O2) and
one water. He did not obtain quinine but rather a dirty dark
brown precipitate. To simplify the experiment, he oxidized
aniline sulfate with potassium dichromate. Once again a dark
precipitate was obtained. Extraction of the precipitate with
alcohol gave a purple dye he named Tyrian Purple, and later
named mauve (mauveine) by the French. Purple dyes were
popular at the time but were unfortunately made from lichens
and bat guano. They also were not fast, i.e., they faded
rapidly. Mauve proved to be both fast and brilliant. The
British stamp, the "pennyred" was
dyed with mauve. Perkin received a patent in 1865 for his
invention, left the Royal College, (much to Hofmann's
displeasure), and established a factory to manufacture
mauve, and eventually, many other dyes.

Benzene was obtained by the distillation of coal tar as
the raw material for the manufacture of mauve. The
distillate, as it was to turn out, was contaminated wth
toluene. Thus, nitration (sodium nitrate and sulfuric acid)
and reduction (iron and acetic acid) gave a mixture of
aniline, o- and p-toluidine. The structure of mauve was
corrected in 1994 and found to be a mixture of mauveine A (major component) and mauveine B(minor component). Where are the aniline, o-
and p-toludine residues in these structures?