The diazonium salts have the general formula ArN2+X-, where X- may be an anion like Cl-, Br- etc.
The group N2+ (-N≡N+) is called diazonium ion group.
Sandmeyer reaction is a substitution reaction.
In the substistution reactions, nitrogen of the salts is lost as N2 and different groups are introduced in its place.
Various substitution reactions of diazonium salts
1. Replacement by -OH group. By boiling or by steam boiling. Phenol is formed
2. Replacement by hydrogen. By treatment with hypophophorous acid. Benzene is obtained.
3. Replacement by Cl and Br group.When the salt is warmed with cuprous chloride or cuprous bromide the corresponding halide is formed. This reaction is called Sandmeyer reaction
Thursday, January 24, 2008
IIT Revision Carbylamine Reaction
Amines Chapter
The treatment of a primary amine with chloroform and alcoholic potash produces carbylamine (isocyanide) which has most offensive smell.
This reaction is not exhibited by secondary and tertiary amines.
The treatment of a primary amine with chloroform and alcoholic potash produces carbylamine (isocyanide) which has most offensive smell.
This reaction is not exhibited by secondary and tertiary amines.
Organic Chemistry Book Download
You can download a book on Organic chemistry from
http://static.scribd.com/docs/a1r2rb5y03vrg.pdf
http://www.scribd.com/doc/3632/Paula-Bruice-Organic-Chemistry-4th-ed
http://static.scribd.com/docs/a1r2rb5y03vrg.pdf
http://www.scribd.com/doc/3632/Paula-Bruice-Organic-Chemistry-4th-ed
Wednesday, January 23, 2008
IIT JEE Revision Ch. 31 Carbohydrates - Core Points
JEE Syllabus
Carbohydrates:
Classification;
mono and di-saccharides (glucose and sucrose);
Oxidation, reduction,
glycoside formation and hydrolysis of sucrose.
----------
1. Carbohydrates means "hydrates of carbon".
These are poly-hydroxylated-aldehydes or poly-hydroxylated-ketones. The general formula is C-x(H-2O)-y
2. Carbohydrates are classified as:
Monosaccharides, Oligosaccharides, Polysaccharides
3. Glucose is a monosaccharide and it forms a six membered ring of five carbon atoms and one oxygen atom.
4. When acqueous solution of glucose is treated with sodium amalgam or sodium borohydride, it is reduced to sorbitol (or glucito) a hexahydric alcohol.
5. Mild oxidizing agents such as bromine water, silver oxide, sodium hypobromite etc. oxidize glucose ot gluconic acid converting -CHO group to -COOH group.
6. The important members belonging to disaccharides are sucrose, maltose and lactose.
7. On hydrolysis these give two molecules of monosaccharides.
8. Sucrose in comination with water (hydrolysis) gives glucose and fructose.
9. Sucrose is composed of alpha-D-glucose and beta-D-fructose. These units are held together by alpha, beta-glycosidic linkage between C1 (carbon 1) of the glucose unit (pyranose ring) and C2 of the fructose unit (furanose ring).
10. Reducing sugars are easily oxidized to give carboxylic acid.
Detailed review points for each topic in the syllabus follow this post. Click Older Post
Carbohydrates:
Classification;
mono and di-saccharides (glucose and sucrose);
Oxidation, reduction,
glycoside formation and hydrolysis of sucrose.
----------
1. Carbohydrates means "hydrates of carbon".
These are poly-hydroxylated-aldehydes or poly-hydroxylated-ketones. The general formula is C-x(H-2O)-y
2. Carbohydrates are classified as:
Monosaccharides, Oligosaccharides, Polysaccharides
3. Glucose is a monosaccharide and it forms a six membered ring of five carbon atoms and one oxygen atom.
4. When acqueous solution of glucose is treated with sodium amalgam or sodium borohydride, it is reduced to sorbitol (or glucito) a hexahydric alcohol.
5. Mild oxidizing agents such as bromine water, silver oxide, sodium hypobromite etc. oxidize glucose ot gluconic acid converting -CHO group to -COOH group.
6. The important members belonging to disaccharides are sucrose, maltose and lactose.
7. On hydrolysis these give two molecules of monosaccharides.
8. Sucrose in comination with water (hydrolysis) gives glucose and fructose.
9. Sucrose is composed of alpha-D-glucose and beta-D-fructose. These units are held together by alpha, beta-glycosidic linkage between C1 (carbon 1) of the glucose unit (pyranose ring) and C2 of the fructose unit (furanose ring).
10. Reducing sugars are easily oxidized to give carboxylic acid.
Detailed review points for each topic in the syllabus follow this post. Click Older Post
IIT Revision Carbohydrates - Introduction
Carbohydrates means "hydrates of carbon".
General names for carbohydrates include sugars, starches, saccharides, and polysaccharides.
The term saccharide is derived from the Latin word " sacchararum" from the sweet taste of sugars.
The chemistry of carbohydrates most closely resembles that of alcohol, aldehyde, and ketone functional groups.
As a result, the modern definition of a CARBOHYDRATE is that the compounds are polyhydroxy aldehydes or ketones.
The general formula is C-x(H-2O)-y
Note that all compounds confirming to the formula are not necessarily carbohydrates
e.g., formaldehyde, CH2O, acetic acid C2H4O2
The chemistry of carbohydrates is complicated by the fact that there is a functional group (alcohol) on almost every carbon.
In addition, the carbohydrate may exist in either a straight chain or a ring structure.
Ring structures incorporate two additional functional groups: the hemiacetal and acetal.
General names for carbohydrates include sugars, starches, saccharides, and polysaccharides.
The term saccharide is derived from the Latin word " sacchararum" from the sweet taste of sugars.
The chemistry of carbohydrates most closely resembles that of alcohol, aldehyde, and ketone functional groups.
As a result, the modern definition of a CARBOHYDRATE is that the compounds are polyhydroxy aldehydes or ketones.
The general formula is C-x(H-2O)-y
Note that all compounds confirming to the formula are not necessarily carbohydrates
e.g., formaldehyde, CH2O, acetic acid C2H4O2
The chemistry of carbohydrates is complicated by the fact that there is a functional group (alcohol) on almost every carbon.
In addition, the carbohydrate may exist in either a straight chain or a ring structure.
Ring structures incorporate two additional functional groups: the hemiacetal and acetal.
IIT JEE Revision Carbohydrate Classification
Based on their solubility in water
Sugars and nonsugars
Based on their chemical constitution
monosaccharides, oliogosaccharides, polysaccharides
Sugars and nonsugars
Based on their chemical constitution
monosaccharides, oliogosaccharides, polysaccharides
IIT JEE Revision Glucose and Sucrose
Glucose (C6H12O6) is a monosaccharide and it forms a six membered ring of five carbon atoms and one oxygen atom.
It is also known as dextrose, grape sugar and blood sugar.
Commercially pure glucose is manufactured by the hydrolysis of starch with dilute H2SO4 under a pressure of 4-5 atmospheres
Sucrose
Sucrose (common name: table sugar, also called saccharose) is a disaccharide (glucose + fructose) with the molecular formula C12H22O11.
Its systematic name is α-D-glucopyranosyl-(1↔2)-β-D-fructofuranose.
The glucose and fructose units are joined by an acetal oxygen bridge in the alpha orientation. The structure is easy to recognize because it contains the six member ring of glucose and the five member ring of fructose.
Pure sucrose is most often prepared as a fine, white, odorless crystalline powder with a pleasing, sweet taste; the common table sugar.
sucrose is a non-reducing sugar.
It is also known as dextrose, grape sugar and blood sugar.
Commercially pure glucose is manufactured by the hydrolysis of starch with dilute H2SO4 under a pressure of 4-5 atmospheres
Sucrose
Sucrose (common name: table sugar, also called saccharose) is a disaccharide (glucose + fructose) with the molecular formula C12H22O11.
Its systematic name is α-D-glucopyranosyl-(1↔2)-β-D-fructofuranose.
The glucose and fructose units are joined by an acetal oxygen bridge in the alpha orientation. The structure is easy to recognize because it contains the six member ring of glucose and the five member ring of fructose.
Pure sucrose is most often prepared as a fine, white, odorless crystalline powder with a pleasing, sweet taste; the common table sugar.
sucrose is a non-reducing sugar.
Subscribe to:
Posts (Atom)