Synthesis of Heterocyclic Derivatives of N- Substituted Phenothiazine

number: 
1158
English
department: 
Degree: 
Author: 
Zahara Sabah Al-Taie
Supervisor: 
Dr.Sawsan H.Shawkat
year: 
2005

The aim of the present work is the synthesis of new derivatives of N-substituted 10H phenothiazine.To obtain these derivatives, the diphenylamine was chosen as the starting material which was heated for 5hrs. with sulfur in presences of iodine, it gave the phenothiazine (1).1- Reaction of phenothiazine with chloro acetyl chloride gave N10- (chloro acetyl) phenothiazine (2), which was treated with hydrazine hydrate to give N10- (acetyl phenothiazine) hydrazine (3) which is the desired product. The hydrazine derivative (3) was reacted with carbon disulfide in presence of KOH to give potassium N10-(acetyl phenothiazine) dithiocarbazate (4) which was refluxed with hydrazine hydrate to give N10-(4-amino-3-mercapto-[1H]-1,2,4- triazin-5-yl)] phenothiazine (5).2- N10-(3-mercapto-[1H,6H]-1, 2, 4-triazin-5-yl) phenothiazine (7) was obtained from the reaction of phenothiazine (1) with thiosemicarbazide to give N10-(acetyl phenothiazine) thiosemicarbazide (6) which suffered intramolecular cyclization when refluxed with basic media ( 2N NaOH) for 3hrs. to give triazine derivative (7).3- Treatment of phenothiazine (1) with thiourea gave N10-(acetyl phenothiazine) thiourea (8), which was used for the preparation of two types of heterocyclic derivatives:

A- The compound N10-(2-amino-[5H]-1, 3-thiazol-5-yl) phenothiazine (9) was synthesized by the intramolecular cyclization of thiourea derivative (8) which was refluxed with conc. H2SO4 for overnight.

B- N10-(2-mercapto-[5H]-1,3-imidazol-4-yl) phenothiazine (10) was synthesized by the intramolecular cyclization of thiourea derivative  (8) through its reflux with (2N NaOH) for 3hrs.

4- Synthesis of N10-[2-([5H]-1, 3-imidazol-4-yl) hydrazine] phenothiazine (11) was obtained from the reaction of compound (10) with hydrazine hydrate.

5- Schiff’s bases: compounds {N10-[(2-[5H]-1, 3-imidazol-4-yl) hydrazone] phenothiazine [12-14]} have been synthesized from the reaction of compound (11), with different aromatic aldehydes.

6- N-[N10-(acetyl phenothiazine)]-4-nitrophenyl hydrazine (15) was synthesized by the reaction of N10-(chloro acetyl) phenothiazine (2) with 4-nitrophenyl hydrazine, which then was treated with phenylisocyanate to give 4N [N10-(acetyl phenothiazine)]-1-phenyl-3-p-nitrophenyl semicarbazide (16).

7-N10- (3- N- phenyl-4- p- bromophenyl-2- hydroxy-4- oxazolin-2- yl) acetyl -2N-nitrophenyl hydrazine (17) was synthesized by the intermolecular cyclization of compound (16) with 4-bromophenancyl bromide

8- Aryl amino acetyl N10-phenothiazine (18-23) were obtained from the reaction N10-(chloro acetyl) phenothiazine (2) with different aromatic amines under refluxing condition.

9- 5-Amino-[3H]-1, 3, 4-thiadiazole-2-thione (24) was obtained from the reflux of carbon disulfide with thiosemicarbazide in presence KOH/abs. EtOH for about 6hrs.

10- N10-(acetyl-5-amino-[3H]-1, 3, 4-thiadiazole-2-thione) phenothiazine (25) was synthesized from the reaction of compound (2) with 5-Amino-[3H]-1, 3, 4-thiadiazole-2-thione (24) under refluxing condition for 24hrs.

All prepared compounds were identified using FTIR technique, melting points and thin layer chromatography.