STEREOCHEMICAL

Keisomeran due to the asymmetric carbon atom, optical keisomeran.

Before there was the theory of valence, chemist / physiologically French Louis Pasteur (1822-1895) have recognized the influence of molecular structure on the properties of individual molecules combined. He managed to separate the racemic tartaric acid (sodium ammonium salt actually) to (+) and (-) under the direction of hemihedral crystal face (1848).
Both compounds have physical properties (eg melting point) and the same chemical, but there are differences in the optical properties in solution of each compound. Both rotate the plane of polarization of light, in other words having an optical activity. Rotation of the second type of compound, which mengkur rotational strength of both compounds, have the same absolute value but opposite sign. Because the molecules are free in solution, this difference can not be explained by differences in crystal structure. Unfortunately at that time, although the existing atomic theory, theory of valence has not been there. With these conditions can not explain the Pasteur discovery.

In the 1860's, the German chemist Johannes Adolf Wislicenus (1835-1902) found that two types of lactic acid is known at that time are both α-hidroksipropanoat acid CH3CH (OH) COOH, instead of acid β-hidroksipropanoat HOCH2CH2COOH. He further suggested that a new concept for menjelaskna stereoisomer should be made for this phenomenon. Konse recently stated that the two compounds that have the same structural formula can be in two dimensu stereoisomer when the arrangement of the atoms in different rooms.
In 1874, van't Hoff and Le Bel independently proposed the theory of tetrahedral carbon atom. According to this theory, the lactic acid that can be depicted in Figure 4.4. One of the lactic acid lactic acid is the mirror image of them. In other words, relations between the two compounds as a relationship right hand and left hand, and therefore called the antipodes or enantiomers. Thanks to the theory of van't Hoff and Le Bel, a new chemistry, stereochemistry, is growing rapidly.

Both isomers or the antipodes, as related to the right and left hand
In the central carbon atom in lactic acid, four different atoms or gigus bound. Carbon atoms are called the asymmetric carbon atom. Generally, the number of stereoisomers will be as many as 2n, n is the number of asymmetric carbon atoms. Tartaric acid has two asymmetric carbon atoms. However, due to the presence of molecular symmetry, the number stereoisomernya less than 2n, and another one is optically inactive stereoisomer (Figure 4.5). All these phenomena can be consistently explained by the theory of tetrahedral carbon atom.

However, because of symmetry, meso-tartaric acid is optically inactive.

Geometrical isomers

Van't Hoff explains fumaric acid and maleic keisomeran because of restrictions on the double bond rotation, a different explanation for the optical keisomeran. Isomers of this type is called the geometrical isomers. In the trans form subtituennya (in the case of fumaric and maleic acid, carboxyl group) are located on different sides of the double bond, while the cis isomer was subtituennya located on the same side.
Of the two isomers are diisoasi, van't Hoff was named isomer which readily releases water into maleic anhydride cis isomer because the cis isomer the two carboxy groups are close to each other. By heating to 300 ° C, acid fuarat turned into maleic anhydride. This is quite logical because the process must involve cis-trans isomerization process of the shipyard which is sufficiently high energies (Figure 4.6) ï ¼ Ž
Because some couples have been known geometrical isomers, geometric isomers theory gives a good dukunagn van't Hoff for the structural theory.

Figure 4.6 maleic acid geometrical isomers (cis form) has two carboxyl groups are close, and easy to release water into anhydride (maleic anhydride).

NITRILE

NITRILE

A nitrile is any organic compound that has a -C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile butadiene rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Organic compounds containing multiple nitrile groups are known as cyanocarbons.

Inorganic compounds containing the -C≡N group are not called nitriles, but cyanides instead. Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic.

Synthesis

Industrially, the main methods for producing nitriles are ammoxidation and hydrocyanation. Both routes are green in the sense that they do not generate stoichiometric amounts of salts.

Ammoxidation

In ammonoxidation, a hydrocarbon is partially oxidized in the presence of ammonia. This conversion is practiced on a large scale for acrylonitrile

CH₃CH=CH₂ + 3/2 O₂ + NH₃ → NCCH=CH₂ + 3 H₂O

A side product of this process is acetonitrile. Most derivatives of benzonitrile as well as Isobutyronitrile are prepared by ammoxidation.

Hydrocyanation

An example of hydrocyanation is the production of adiponitrile from 1,3-butadiene:

CH₂=CH-CH=CH₂ + 2 HCN → NC(CH₂)₄CN

From organic halides and cyanide salts

Often for more specialty applications, nitriles can be prepared by a wide variety of other methods. For example, alkyl halides undergo nucleophilic aliphatic substitution with alkali metal cyanides in the Kolbe nitrile synthesis. Aryl nitriles are prepared in the Rosenmund-von Braun synthesis.

Cyanohydrins

The cyanohydrins are a special class of nitriles that result from the addition of metal cyanides to aldehydes in the cyanohydrin reaction. Because of the polarity of the organic carbonyl, this reaction requires no catalyst, unlike the hydrocyanation of alkenes.

Dehydration of amides and oximes

Nitriles can be prepared by the Dehydration of primary amides. Many reagents are available, the combination of ethyl dichlorophosphate and DBU just one of them in this conversion of benzamide to benzonitrile:

Two intermediates in this reaction are amide tautomer A and its phosphate adduct B.

In a related dehydration, secondary amides give nitriles by the von Braun amide degradation. In this case, one C-N bond is cleaved. The dehydration of aldoximes (RCH=NOH) also affords nitriles. Typical reagents for this transformation arewith triethylamine/sulfur dioxide, zeolites, or sulfuryl chloride. Exploiting this approach is the One-pot synthesis of nitriles from aldehyde with hydroxylamine in the presence of sodium sulfate.

• from aryl carboxylic acids (Letts nitrile synthesis)

Sandmeyer reaction

Aromatic nitriles are often prepared in the laboratory form the aniline via diazonium compounds. This is the Sandmeyer reaction. It requires transition metal cyanides.

ArN₂⁺ + CuCN → ArCN + N₂ + Cu⁺

Other methods

• A commercial source for the cyanide group is diethylaluminum cyanide Et₂AlCN which can be prepared from triethylaluminium and HCN. It has been used in nucleophilic addition to ketones. For an example of its use see: Kuwajima Taxol total synthesis

WASTE LACTAM

Types of waste can be a beta lactam liquid waste, solid, air, and noise. Liquid waste from the production of beta-lactam building a washing tool / machine. Solid waste container in the form of raw materials used beta-lactam antibiotics, beta-lactam raw materials are damaged, plastic cans, waste production, and the finished product defective beta-lactam antibiotics. Air waste in the form of beta-lactam antibiotic production of dust. Waste production of the sound coming from the engine, generator, engine support systems (AHU).
Waste Management of beta-lactam is as follows:
a. Liquid Waste
Liquid waste from the building flows into the bed of beta lactam / beta-lactam ring of destruction pool by using NaOH solution, after it is passed / non liquid wastes combined with beta-lactams in the reservoirs, and so on processed together.
b. Solid Waste
Solid waste containers that contain a beta-lactam antibiotics are washed and rinsed thoroughly with clean water in the washing space in the building of beta-lactam. Washing water is wastewater from buildings that are drawn to beta-lactam ring of beta-lactam like destroyers, while the container which had been washed and rinsed clean the building out of beta lactam and wastes handled as solid waste management in non-beta-lactams.
c. Waste Air
Waste air aspirated and the production of dust collected by dust collector.
d. Sound waste
Sound waste is derived from the production machine, generator, engine support systems (AHU, boilers machinery). Sound waste control measures can be overcome by using ear insert by the workers. Benchmark used for the monitoring of waste is the number of sound and vibration noise inside and outside the plant area measured in accordance with 65 dB maximum noise figure and maximum vibration of 7.5 Hz.
The main principle in waste management is the solution of beta-lactam beta-lactam cicncin. Some ways of solving cicncin beta lactam can be done in the following way (Encyclopedia of Chemical Technology, 1952):
A. Hydrolysis by raising the pH to 10-12 (can denganNaOH)
2. With the addition of acid hydrolysis
3. Hydrolysis with the addition of mercury chloride
The use of the means by hydrolysis with a pH of 10-12 to become one of the alternative most companies because it is considered safer for the equipment and the processing unit is also environmentally safe and easy bai in handling. If the acid hydrolysis feared could damage equipment pengelohan unit because the nature of corrosive acids that can cause, and if the mercury chloride mercurynya feared unfriendly or unsafe for the environment.
The results from the hydrolysis tank flowed into the neutralization tank to neutralize alkaline hydrolysis with NaOH after the addition of HCl so that the resulting pH is in accordance with normal pH is 6-9. Setela neutralization process then continued with the deposition process. Adsorbs to organic matter and a ring beta-lactam that may remain in the wastewater, as well as to eliminate the possibility of the presence of heavy metal content, the beta-lactam treatment unit equipped with a tub filtration. Produced from waste treatment unit of beta lactam can then be measured by HPLC (hig Performance Liqiud Cromatography).

ORGANIC CHEMISTRY II

  Amide
DEFINITIONS
Each one of the members of two classes that contain nitrogen in senyawaorganik, always contains a carbonyl group (-C = O). The first class, amide kovalendibentuk by replacing the hydroxyl group (-OH) of the amino acid group (-NR2, where R may represent a hydrogen atom or an organic combining group such as methyl). Amide formed from carboxylic acids, called
carboxamides
, Is padatankecuali for the most simple, is in the form of liquid formamide. Amide does not conduct electricity, has a high boiling point, and (when liquid) is a solvent that baik.Tidak no natural sources of simple covalent amide practical, but the peptide and proteindalam living systems is a long chain (polymer) with a peptide bond. Adalahsuatu urea amides with two amino groups. Commercial amides, including some kovalendigunakan as solvent, while the other is a sulfa drug and nylon. The second class, the amide ions (such as salt), prepared by treating a covalent amide, amine atauamonia with reactive metals (eg sodium) and alkaline kuat.Sebuah derivatives of carboxylic acids with RCONH2

as a general formula, where Radalah hydrogen or alkyl or aryl radical. Amida is divided into several sub-classes, depending on the number of substituents on the nitrogen. Simple or primary, that is amidadibentuk by replacing the carboxylic hydroxyl group by an amino group, NH2
. Inidiberi compound name by dropping acid "-ic" or "-OIC" from the name origin danmenggantinya carboxylic acid with the suffix 'amide'. In secondary and tertiary amides, one ataukedua hydrogen is replaced by other groups. The presence of the prefix tersebutditunjuk group N (for nitrogen). Except for formamide, all the simple amides is melted solid, stable, danasam weak. They are strongly associated through hydrogen bonding, so soluble in the solvent
hydroxylic
, Such as water and alcohol. Because of the ease of formation and a sharp melting point, amides are often used for identification of organic acids and amines identification. Persiapankomersial amide involves thermal dehydration of the carboxylic acid ammonium salt.

amide
Amide is the type of compounds that can have the first two terms. TYPE is an organic functional group having a carbonyl group (C = O), which binds to a nitrogen atom (N), or a compound that contains this functional group. The second type of anion suatubentuk nitrogen. Amide NH groups 2
can be dehydrated to a nitrile
The nature of Amida


Amide is a compound that is reactive, because the protein consists of amino acids linked by amide bonds. Amide does not react with halide ions, ionkarboksilat, alcohol, or water because in each case, the incoming nucleophile is a weak base of the amide group to go

Molecular orbital theory can explain why the amide is not reactive. Amide has an important resonance contributor in which one partner shares with nitrogen karbonkarbonil, which contains a lone pair orbital overlap of the empty orbitals of the cluster karboni
Lower energy state overlap-one basis is not a partner or nucleophilic, and increase the orbital energy of the carbonyl group, making it less reactive to nucleophiles
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