Archive for June, 2010
synthesis OF t-alcohols
Tertiary alcohols, R1 R2 R3.COH, may be synthesised by
Action of the Grignard reagent upon diethyl carbonate
In: Uncategorized · Tagged with: ALCOHOLS, synthesis
amino acid as bipolar ion
amino acid as bipolar ion
although the amino acid are commonly shows as containing an amino group, H2NCHRCOOH, certain chemical and physical are not consist with structure.
a. the amino acid are nonvolatile crystalline solid which melts with decomposition at fairly high temperature .
They are insoluble in polar solvent lick petroleum-ether,ether ,Benzine , [...]
In: Theory · Tagged with: amino acid, bipolar ion
CHARACTERISATION OF UNSATURATED ALIPHATIC HYDROCARBONS
CHARACTERISATION OF UNSATURATED ALIPHATIC HYDROCARBONS
Unlike the saturated hydrocarbons, unsaturated aliphatic hydrocarbons are soluble in concentrated sulfuric acid and exhibit characteristic reactions with dilute potassium permanganate solution and with bromine.Nevertheless, no satisfactory derivatives have yet been developed for these hydrocarbons, and their characterization must therefore be based upon a determination of their physical properties (boiling point, [...]
In: Molecules · Tagged with: HYDROCARBONS
UREA
UREA
Wohler’s classical synthesis of urea from ammonium cyanate may be carried
out by evaporating solutions of sodium cyanate and ammonium sulphate
In aqueous solution at 100° the change is reversible and equilibrium is reached when 95 per cent, of the ammonium cyanate has changed into urea. Urea is less soluble in water than is ammonium sulphate, hence [...]
In: Uncategorized · Tagged with: UREA
METHYLENE IODIDE
METHYLENE IODIDE DISTILLATION
In a 1-litre three-necked flask, fitted with a mechanical stirrer, reflux condenser and a thermometer, place 200 g. of iodoform and half of a sodium arsenite solution, prepared from 54′5 g. of A.R. arsenious oxide, 107 g. of A.R. sodium hydroxide and 520 ml. of water. Start the stirrer and heat the [...]
In: Synthetic Chemistry · Tagged with: DISTILLATION
Pseudo-saccharin ethers
Pseudo-saccharin ethers.
Pseudo-saccharin chloride reacts with alcohols to give ethers (0-alkyl derivatives of
saccharin) :
Heat a little pseudo-saccharin chloride with excess of the anhydrous alcohol in a test-tube until hydrogen chloride is no longer evolved. Recrystallise from alcohol or other organic solvent. With the lower primary alcohols, heating at 100° for 10 minutes uffices: [...]
In: Uncategorized · Tagged with: Pseudo-saccharin ethers
3:4: 5-Triiodobenzoates.
3:4: 5-Triiodobenzoates.
The derivatives enumerated above are unsatisfactory for alcohol – ethers, e.g., the mono-ethers of ethyleneglycol (” cellosolves “) and the mono-ethers of diethyleneglycol (” carbitols”) .Crystalline derivatives of alcohol – ethers are readily obtained with 3 : 4 : 5-triiodobenzoyl chloride ,
for example : Place 0-5 g. of 3 : 4 : [...]
In: Reaction Mechanisms · Tagged with: 3:4: 5-Triiodobenzoates.
Differentiation between primary, secondary, and tertiary alcohols (Lucas test)
Differentiation between primary, secondary, and tertiary alcohols
(Lucas test).
The test depends upon the different rates of formation of the alkyl chlorides upon treatment with a hydrochloric acid – zinc
chloride reagent * (containing 1 mole of acid to 1 mole of anhydrous zinc chloride) and with hydrochloric acid. It applies only to aliphatic and cycfoaliphatic alcohols.To 1 [...]
In: Name Reactions · Tagged with: ALCOHOLS
ALCOHOLS
REACTION OF ALIPHATIC ALCOHOLS WITH ACETYLE CHLORIDE.
Treat 1 ml. of the alcohols enumerated
in (iv) cautiously with 0-5-0-7 ml. of acetyl chloride. Observe the
reaction which occurs. After 2-3 minutes, pour the contents of the
various test-tubes into 3 ml. portions of water, neutralise the aqueous
layer with solid sodium bicarbonate, and examine the residual liquids
for [...]
In: Uncategorized · Tagged with: ALCOHOLS
ALCOHOLS
REACTIONS OF ALIPHATIC ALCOHOLS with sodium.
Treat 2 ml. of absolute methyl alcohol with a small thin slice of dry, freshly-cut sodium Observe the result. Cool the solution when all the sodium has reacted. Add a little water and test the solution with litmus paper. Obtain five small dry test-tubes and introduce 1 ml. of the [...]
In: Uncategorized · Tagged with: ALCOHOLS