DIAZOTISATION

DIAZOTIZATION : 

DIAZOTIZATION BY J.RAMANAND BABU (M.PHARMACY 1 ST YEAR)

WHAT IS DIAZONIUM COMPOUND?: 

WHAT IS DIAZONIUM COMPOUND?

INTRODUCTION:-: 

INTRODUCTION:- Diazotization is used in the analysis of aromatic compounds containing an amino group in the molecules. It is based on the reaction between aromatic primary amine (–NH2)and HONO in presence of excess mineral or inorganic acids.

PRINCIPLE:-: 

PRINCIPLE:- NaNO 2 is generally used in direct method of diazotization. It gives HNO 2 in acidic solution. Many aromatic primary amine with free –NH 2 group can be analyzed quantitatively by measuring the volume of NaNO 2 solution required to convert them into DIAZONIUM salts.

REACTION:-: 

REACTION:- The typical reaction of diazotization reaction in presence of HCl is given as:- NaNO 2 + HCl HONO + NaCl ArNH 2 + HONO + HCl ArN 2 Cl + 2H 2 O

PRINCIPLE:-: 

PRINCIPLE:- When all the aromatic amine has reacted with NaNO 2 then next portion (excess) of NaNO 2 added to the solution under test, converted to HONO that remain in the solution. It can be detected by the starch paper or paste as an external indicator. This appearance of free HNO 2 in solution indicates that diazotization reaction is complete and equivalence point is attained

INDICATOR:-: 

INDICATOR:- Starch iodide paper or paste is the starch solution Plus equal volume of 5% KI solution in H 2 O. Starch iodide paste with reaction mixture is as follows- KI + HCl HI+ KCl 2HI + 2 HONO I 2 ↑ + 2NO + 2H 2 O (excess) I 2 + Starch blue color (end point) The liberated I 2 reacts with starch to give blue colour .

CONDITION FOR DIAZOTIZATION:-: 

CONDITION FOR DIAZOTIZATION :- 1. Rate of titration. 2. Temperature of the solution.

Drugs assayed by sodium nitrite titration: 

Drugs assayed by sodium nitrite titration (1) Dapsone - Antileprotic drug . (2) Benzocaine – Localanaesthetic . (3) Procaine hydrochloride- Local anaesthetic . (4) Calcium amino salicylate-Antitubercular . (5) Sodium amino salicylate-Antitubercular . (6) Sulphacetamide tablet-Acne and dermatitis. (7) Sulphadoxine-Antimalarial . (8) All sulpha drugs.

ASSAY OF SUCCINYLSULPHATHIAZOLE: 

ASSAY OF SUCCINYLSULPHATHIAZOLE Dissolve weighed sample in a mixture of Hcl and water. Reflux for 1 hour. Titrate slowly with 0.1M NaN0 2 until blue colour is produced. Take a drop of titrated solution and place it on a thin layer of starch iodide paste.

REFERENCES: 

REFERENCES Practical pharmaceutical chemistry by:-A.H.Beckett and J.B.Stenlake. Vogels textbook of pharmaceutical analysis. Method of Analysis and Assay: Miscellaneous Methods of Analysis by :- Dr. M. Shahar Yar.

THANK YOU: 

THANK YOU