Synthesis of some new antipyrine derivatives

Abstract EN

In this work, 4-chloro acet amide derivative [2] was prepared from 4-amino antipyrine [1] and chloro acetyl chloride then converted into thiozolidine-4-one [3] on reaction with KSCN.

Subsequent refluxing of compound [3] with 3 nitrobenzaldehyde in the presence of NaOAC-acetic acid gave the derivative [4].

The hydrazide derivative [5] was prepared from the 4-chloro acet amide derivative [2] and hydrazine hydrate, which upon refluxing with acetyl aceton in absolute ethanol yielded antipyrine containing pyrazol moiety [6], refluxing of compound [2] with some amines in absolute ethanol afford the corresponding acetamide derivatives [7-10].

Moreover, reaction of [1] with CS2 and KOH afforded the salt [11], which upon reaction with hydrazine hydrate at 45-55oC for 1hr, yielded the fused ring derivative [12].

The Schiff base [13] was prepared from 3-nitro benzaldehyde and compound [1], and then oxidized by KMno4 into the acid derivative [14].

Diazotization of compound [1] with NaNo2 / HCl led to azo derivative [15] which is reacted with acetyl acetone to give compound [16].

Reaction of compound [[16] with hydrazine led to ring closure giving derivative with pyrazole moiety [17].

Furthermore, reaction of [1] with tetrahydrofuran in acetic acid gave derivative with pyrrolidin moiety [18].