EXPERIMENT No: - 1 AIM: - Synthesis of p-Nitro aniline from Acetanilide.REAGENTS: -Acetanilide, Glacial acetic acid, Conc. HNO3, Conc. H2SO4

REACTION: -

PROCEDURE: - Add dry acetanilide (25 g) to glacial acetic acid (25 ml) in a beaker

and then introduce concentrated sulphuric acid (50 ml) slowly with constant stirring to

obtain clear solution. Place the beaker in a freezing mixture of ice and salt to cool the

solution below 5 oC. Add a cold mixture of concentrated nitric acid (11 ml) and

concentrated sulphuric acid (7 ml) drop wise with constant stirring to a reaction mixture

while maintaining the temperature below 5 oC. After adding all the mixed acid, remove

the beaker from the freezing mixture and keep it for 1 hr at room temperature. Pour the

reaction mixture into an ice cold water (30 ml) to obtain the crude product of p-

nitroacetanilide. Filter it on suction, wash with cold water till free from acid and

recrystallize the pale yellow product from ethanol to get colourless crystalline solid, m.p.

2145 oC.

NOTE: - o-Nitroacetanilide remains in the filtrate due to its more solubility in water.

EXPERIMENT No: - 2 Date: -

AIM: - Synthesis of Benzillic acid from Benzoin.

REAGENTS: - Benzoin, Glacial acetic acid, Conc. HNO3,

Benzil, KOH, Methanol, Conc, H2SO4

REACTION: - Step 1

Step 2

PROCEDURE: -

Step 1: - Heat a mixture of benzoin (1 g), glacial acetic acid (5 ml) and conc. nitric acid

(25 ml) in a test tube on boiling water bath for one hour. Then, pour down the contents

into ice cold water (50 ml) with continuous shaking. Filter the product, wash the solid

with cold water, and recrystallize from methanol, m.p. 92 oC.

Step 2: - Dissolve KOH (7 g) in water (15 ml) by heating on hot plate and the cool to

room temperature. Disolve benzyl (7 gm) in methanol by heating on a water bath for 15

minutes. Cool down the contents and pour into alkali solution with stirring. Reflux the

content on a water bath till blue colour disappears. Cool in ice, collect the colorless

needles pot. Benzillate. Dissolve the solid in minimum quantity of hot water and acidify

with HCl. Collect the solid benzillic acid and recrystallize from ethanol.

RESULT: - (1) Theoretical yield = ____________gm (2) Practical yield = ____________gm

(3) % of yield = ____________ % (4) Melting point = ____________ oC.

EXPERIMENT No: - 7Date: -

AIM: - Synthesis of Chalcone (1, 3-diphenylprop-2-en-1- one) from Bendzaldehyde and Acetophenone.

REAGENTS: - Bendzaldehyde, Acetophenone, NaOH, Rectified spirit

REACTION: -

PROCEDURE: - Place a solution of 22 g of sodium hydroxide in 200 ml of water and

100 g (122.5 ml) of rectified spirit in a 5000 ml bolt-head flask provided with a

mechanical stirrer. Immerse the flask in a bath of crushed ice, pour in 52 g (0.43 mol) of

freshly distilled acetophenone, start the stirrer and then add 46 g (44 ml, 0.43 mol) of

pure benzaldehyde. Keep the temperature of the mixture at about 25 oC (the limits are 15-

30 oC) and stir vigorously until the mixture is so thick that stirringis no longer effective

(2-3 hours). Remove the stirrer and leave the reaction mixture in an ice chest or

refrigerator overnight. Filter with cold water until the washings are neutral to litmus, and

then with 20 ml of ice-cold rectified spirit. The crude chalcone, after drying in the air,

weighs 88 g and melts at 50-54 oC . Recristallinse from rectified spirit warmed to 50 oC

(about 5 ml per gram). The yield of pure chalcone (a pale yellow solid), m.p. 56-57 oC, is

77 g (85%). This substance should be handled with care since it acts as s skin irritant.

RESULT: - (1) Theoretical yield = ____________gm (2) Practical yield = ____________gm

(3) % of yield = ____________ % (4) Melting point = ____________ oC.

EXPERIMENT No: - 8Date: -

AIM: - Synthesis of Barbituric acid from Urea and Dimethyl malonate.

REAGENTS: - Urea, Dimethyl malonate, Sodium metal, Absolute Ethanol

REACTION: -

PROCEDURE: - In a 2-litre round bottomed flask, fitted with a double surface reflux

condenser, place 11.5 g (0.5 mol) of clean sodium. Add 250 ml absolute ethanol in one

portion: if the reaction is unduly vigorous, immerse the flask momentarily in ice. When

all the sodium has reacted, add 80 g (76 ml, 0.5 mol) of diethyl malonate, followed by a

solution of 30 g (0.5 mol) of dry urea in 250 ml of hot (about 70°C) absolute ethanol.

Shake the mixture well, fit a calcium chloride guard-tube to the top of the condencer and

reflux the mixture for 7 hours in an oil bath heated to 110°C. A white solid separates.

Treat the reaction mixture with 450 ml of hot (50°C) water and then with concentrated

hydrochloric acid, with stirring, until the solution is acidic (about 45 ml). Filter the

resulting almost clear solution and leave it in the refrigerator overnight. Filter the solid at

pump, wash it with 25 ml of cold water, drain well and then dry at 100°C for 4 hours.

The yield of barbituric acid is 50 g (78%). It melting point of product is 245°C.

RESULT: - (1) Theoretical yield = ____________gm (2) Practical yield = ____________gm

(3) % of yield = ____________ % (4) Melting point = ____________ oC.