Synthesis and Spectroscopic Study on 4-(Phenoxathiin- 2-yl)phthalazine Derivatives

Abstract

This work aims to synthesize some new phenoxathiin derivatives and to study their spectral and biological activity.

This work is divided to three parts:

Part 1:

It involves determination of the site of electrophilic substitution on phenoxathiin using ab intio calculations.

Also, involve synthesis of 4-(phenoxathiin-2-yl)phthalazin-1(1H)-one (5)

• and its mercopto derivative (7) and both reacted with different phtha1yl and tosyl amino acid using carbodiimide technique to give 1-N-[pht.(tos.)aminoacyloxy]- 4-(phenoxathiin-2-yl) phthalazines (9a-e) and (lla-e) and the conesponding

mercapto derivtives (12a-e) and (13a-e).

On the other hand, the deprotected amino acid derivatives (14a-e) and

(15a-e) were obtained.

Part 2:

It involves synthesis of 1-hydrazino-4-(phenoxathiin-2-yl)phthalazine (16) and its reactions with various aromatic aldehydes, diethyl oxalate and phenyl isothiocynate to give (17a-d), (18) and (19) respectively.

Also, it involves synthesis of acid (20) which was employed m the synthesis of dipeptide (22a-b).

On the other hand, aminothiadiazole moiety (24) was synthesized and was allowed to react with aromatic aldehydes, acetyl chloride and phenyl isothiocynate to give the conesponding Schiff base,amide and thiourea derivatives respectively.