To prepare and submit 3-methyl-1-phenyl pyrazole-5-one (Paal-Knorr synthesis) .

 Aim: To prepare and submit 3-methyl-1-phenyl pyrazole-5-one (Paal-Knorr synthesis) from methylacetoacetate.

Reference:

Furnish B.S, Hanford A.J. "Vogel's Textbook of organic chemistry" longmann scientific and technical UK Ltd. 5th edition 1989 pp_

Requirements: Ethyl acetoacetate, phenyl hydrazine, ether, ethanol, round bottom flask, pipette,beaker,funnel etc

Theory: 3-Methyl-1-phenyl pyrazole-5-one is synthesized by condensation of phenyl hydrazine and ethyl acetoacetate under basic condition.

Reaction involved:

Procedure:

1.Heat a mixture of phenyl hydrazine (3.65 ml) and ethyl acetoacetate (4.9 ml) in a 250 ml round bottom flask on boiling water bath for 2 hours.

2.Stir the reaction mixture with the help of a glass rod.

3.Cool the reaction mixture and then add 20 ml ether with stirring.

4.Filter the separated product, wash with ether and recrystallize with dilute ethanol (1:1).

Melting point of the product is 127°C.

Calculation:

Theoretical yield =

Practical yield =

Percentage of yield =Practical yield ×100

                                     Theoretical yield

Results: The yield of obtained product was found to be _____gm and percentage yield was'"_____% 

Uses: It is an example of intermediate used in bulk drug industry.

Caution: Glassware should be clean and dry before being used.

 Pryazole synthesis,

Synthesis reaction of pyrazole,

Prepration of pyrazole.