Organic Pharmacy II Lab Manual - Primeasia University

Department of Pharmacy Primeasia University Bachelor of Pharmacy (B. Pharm) Lab Manual Course title: Organic Pharmacy-II Practical Course code: PHR 1204L Experiment Number: 1 Experiment Name: Functional Group Determination (Test for aldehyde group (-CHO)) Samples:...

Department of Pharmacy Primeasia University Bachelor of Pharmacy (B. Pharm) Lab Manual Course title: Organic Pharmacy-II Practical Course code: PHR 1204L Experiment Number: 1 Experiment Name: Functional Group Determination (Test for aldehyde group (-CHO)) Samples:  Formaldehyde, HCHO  Benzyldehyde,C6H5.CHO  Veneline.CH3O.C6H39(OH).CHO Chemicals & reagents:  Fehling’s solution  Tollen’s reagent  Ethanol  Benedict’s reagent  Water Glass ware:  Test tube  Dropper  Test tube Holder  Water bath Procedure: A) Fehling’s solution (A+B) Test: Few drops of liquid compound has been taken and add water (if insoluble add ethanol) in a test tube. Then fehlings’ solution (A+B same reaction) has been added to the test tube and shake well. Heat the test tube boiling water bath for 15 minutes. Observation: A red color of cuprous ppt has been observed. Result: Aldehyde(-CHO) group is present. Reaction: RCHO + Cu(OH)2 + NaOH → Cu2O↓ + RCOONa +H2O Red B) Reaction with Tollen’s reagent: Add 30 mg of the compound (if liquid 1 ml compound+ 1 ml H2O) to 2 ml of reagent in a clean test tube. Allow it to test tube stand for 10 minutes, if no reaction occurs, place the tube in a water bath at about 35°C for minutes. Observation: Silver mirror has been observed. Result: Aldehyde (-CHO) group is present. Reaction: C6H5CHO + AgNO3 +NH4OH → Ag ↓ + C6H5COONH4 + NH4NO3 + H2O {N.B. only aromatic aldehydes show the positive test with Tollens reagent} C) Reaction with Benedict’s reagent: Take few mg/1 ml compounds and add Benedicts’ reagent then heat the test tube. Observation: A yellow to orange colored ppt or suspension is observed. Result: Aldehydes (-CHO) group is present. [N.B. only aliphatic aldehydes show the positive test with Fehling and Benedicts reagent] Experiment Number: 2 Experiment Name: Functional Group Determination (Test for Ketone group (>C=O)) Samples:  Acetone, CH3CO.CH3  Diethyl ketone, C2H5.CO.C2H5  Benzyl acetone, C6H5.CH:CH.CO.CH3 Chemicals & Reagents:  5% Sodium Nitroprosside solution  30% NaOH  Alcohol  Glacial Acetic acid  Water Glass ware:  Test tube  Dropper  Test tube Holder Procedure: [Compound which give the test for 2, 4 –Dinitrophenyl hydrazine positive but gave negative test for aldehyde are considered test as ketones] Few mg or 1 ml compound has been taken and add equal volume of water (if insoluble add alcohol) then add 1 drop of 5% sodium nitroprosside solution and 1 drop 30% NaOH Observation: A red or yellow colour ppt. After adding 1 or 2 drops of glacial acetic acid, then red or blue colour ppt forms. Result: Ketone(>C=O) group is present. Experiment Number: 3 Experiment Name: Nitrogen containing Functional group determination (Test for Amino group (-NH2)) Samples:  Aniline  P-toluidine  β-napthayl amine  O-phenyl di amine  Salfanilic acid Chemicals & Reagents:  2.5% solution of quinhydrone in methanol  Ethanol  NaOH  CHCl3  Acetone  1% sodium nitropruside solution  Conc. H2SO4  10% NaNO2  Sodium napthoxide (β-napthol + 10% NaOH)  Water Glass ware:  Test tube  Dropper  Test tube Holder  Burner  Electrical balance  Spatulla Procedure: Quinhydrone test: Place 6ml water in a test tube and add (15-20) mg or 1-2 drops sample [ if the sample dissolve add more 2 ml water or if the sample did not dissolve in the water then add 6 ml ethanol] and add 1 drop of 2.5% solution of quinhydrone in methanol. Observation: Aliphatic amines produce color with only one drop of the reagent. Result: Violet color Primary Amines Rose-pink color Secondary Amines Yellow color Tertiary Amines Aryl amines generally do not produce any color with only 1 drop of reagent then add 5 more drops of the quinhydrone reagent allow it to stand 2 minutes. Result: Rose color Primary Amines Amber color Secondary Amines Yellow color Tertiary Amines Experiment Number: 4 Experiment Name: Nitrogen containing Functional group determination (Test for urea & substituted amine) ( -CONH2 group ) / Thiourea test ( -CSNH2 group)) Samples:  Benzamide  Urea  Thalamide  Phenyl acetamide  Thiourea Chemicals & Reagents:  NH3  10% NaOH & 20% NaOH  CuSO4 dilute  10% FeCl3  KOH solution  Lead acetate  10% CuSO4  Water Glass ware:  Test tube  Dropper  Test tube Holder  Burner  Filter paper Biuret test: Take 3-4 mg compound, heat for 2-3 minutes in a test tube. NH3 evolves & the residue solidifies with the formation of Biuret. Dissolve residue 10% NaOH warm and cool. Add 2 drops very dilute CuSO4. Observation: A violet color is observed. Result: Urea is present. Reaction: CO(NH2)2 → NH3+ HCNO HCNO + NH2CONH2→ NH2CNHCONH2 + CuSO4 Violet colour Thiourea test: A) FeCl3 test: Take 3-4 mg compound, heat for 1 minutes in a test tube. Add 3-4 drops water then add 2-3 drops 10% FeCl3 solution. Observation: A blood red color is observed. Result: Thiourea is present. Reaction: NH2-CS-NH2 →NH4SCN + FeCl3 → Fe(SCN)Cl2 + NH4Cl B) Lead acetate test: Take 3-4 mg compound, heat for 1 minutes in a test tube and add 2 ml KOH solution then add 1- 2 drops of lead acetate solution. Observation: A black color ppt is observed. Result: Thiourea is present.