Aleksandr Pavlovich Dianin (russian: Александр Павлович Дианин; 20 April 1851 – 6 December 1918) was a
Russian
Russian(s) refers to anything related to Russia, including:
*Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries
*Rossiyane (), Russian language term for all citizens and peo ...
chemist
A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe t ...
from
Saint Petersburg
Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...
. He carried out studies on
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it ...
s and discovered a phenol
derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...
now known as
bisphenol A and the accordingly named
Dianin's compound
Dianin's compound (4-''p''-hydroxyphenyl-2,2,4-trimethylchroman) was first prepared by Aleksandr Dianin in 1914. This compound is a condensation isomer of bisphenol A and acetone and of special importance in host–guest chemistry because it can f ...
.
He was married to the adopted daughter of fellow chemist
Alexander Borodin. In 1887, Dianin succeeded his father-in-law as chair of the Chemistry Department at the Imperial Medical-Surgical Academy in St. Petersburg (now the
S.M. Kirov Military Medical Academy).
Bisphenol A and Dianin's compound
Dianin's method for preparing
bisphenol A from 1891
remains the most widely-known approach to this important compound,
though the method has been refined for industrial-scale synthesis.
It involves the
catalysed
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
condensation of a 2:1 mixture of
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it ...
and
acetone
Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour.
Acetone is miscib ...
in the presence of concentrated
hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid
Acid strength is the tendency of an acid, symbol ...
or
sulfuric acid. The reaction proceeds readily at room temperature producing a crude product containing a great variety of side products (including
Dianin's compound
Dianin's compound (4-''p''-hydroxyphenyl-2,2,4-trimethylchroman) was first prepared by Aleksandr Dianin in 1914. This compound is a condensation isomer of bisphenol A and acetone and of special importance in host–guest chemistry because it can f ...
) in a matter of hours.
The overall equation is simple, with water as the only
by-product:
![Synthesis Bisphenol A](https://upload.wikimedia.org/wikipedia/commons/0/07/Synthesis_Bisphenol_A.svg)
Mechanistically, the acid catalyst converts the acetone to a
carbenium ion
A carbenium ion is a positive ion with the structure RR′R″C+, that is, a chemical species with a trivalent carbon that bears a +1 formal charge.
In older literature the name carbonium ion was used for this class, but now it refers exclusivel ...
that undergoes an
electrophilic aromatic substitution
Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic n ...
reaction with the phenol, producing predominantly
''para''-substituted products. A second carbenium species is produced by protonation and loss of the aliphatic
hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydro ...
group, leading to bisphenol A (4,4'-isopropylidenediphenol) after a second aromatic substitution reaction. The process is not very selective, and a great number of minor products and side reactions are known.
![Dianin](https://upload.wikimedia.org/wikipedia/commons/d/d5/Dianin.svg)
Side products that are
isomers of bisphenol A result from the formation of ''ortho''-substituted products, and include the 2,2'- and 2,4'- isomers of isopropylidenediphenol. Other side reactions include the formation of
triphenol I, 4,4'-(4-hydroxy-''m''-phenylenediisopropylidene)diphenol, from the attack of a carbenium
electrophile
In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carrie ...
on a bisphenol A molecule and the formation of
triphenol II, 4,4',4
''-(2-methyl-2-pentanyl-4-ylidene)triphenol, when an
elimination reaction
An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one- or two-step mechanism. The one-step mechanism is known as the E2 reaction, and the two-step mechanism is known as the E1 r ...
converts the carbenium to a reactive
olefin.
Catalysed
dimerisation of acetone via an
aldol condensation
An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to ...
is well known, and yields
diacetone alcohol and (by
dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
)
mesityl oxide
Mesityl oxide is a α,β-unsaturated ketone with the formula CH3C(O)CH=C(CH3)2. This compound is a colorless, volatile liquid with a honey-like odor.
Synthesis
It is prepared by the aldol condensation of acetone to give diacetone alcohol, whic ...
in both acidic and basic conditions.
The ''in situ'' generation of mesityl oxide adds another reactive olefin to the mixture. In cases where an olefinic
moiety
Moiety may refer to:
Chemistry
* Moiety (chemistry), a part or functional group of a molecule
** Moiety conservation, conservation of a subgroup in a chemical species
Anthropology
* Moiety (kinship), either of two groups into which a society is ...
can interact with a phenolic hydroxyl group (typically as a result of ''ortho''-substitution), rapid
cyclisation
A cyclic compound (or ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where ...
reactions producing
flavan
The flavans are benzopyran derivatives that use the 2-phenyl-3,4-dihydro-2''H''-chromene skeleton. They may be found in plants. These compounds include the flavan-3-ols, flavan-4-ols and flavan-3,4-diols (leucoanthocyanidin).
A ''C''-glycosidic fl ...
s and
chroman
Chromane (benzodihydropyran) is a heterocyclic chemical compound with the chemical formula C9H10O. Chromane is a structural feature of more complex compounds including E vitamins (tocopherols and tocotrienols), Dianin's compound, and the pharmac ...
s occur.
This is the source of Dianin's compound in the mixture, and Dianin subsequently demonstrated that the compound can be produced in much greater yield by reacting phenol with mesityl oxide directly.
Later work has shown that production of bisphenol A can be made much more selective by using a reaction mixture with a considerable excess of phenol rather than a
stoichiometric
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions.
Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equ ...
2:1 composition, greatly suppressing side reactions.
References
Further reading
*
*
{{DEFAULTSORT:Dianin, Alexander
1851 births
1918 deaths
People from Vladimir Oblast
Inventors from the Russian Empire
Chemists from the Russian Empire
University of Jena alumni
S.M. Kirov Military Medical Academy alumni
19th-century chemists