Download (4Mb) - Etheses - Saurashtra University

Chapter – 3 Preparation of small library…..
3.6 SPECTRAL DISCUSSION
3.6.1 MASS SPECTRAL STUDY
Mass spectra of the synthesized compounds were recorded on
Shimadzu GC-MS QP-2010 model using direct injection probe technique.
The molecular ion peak was found in agreement with molecular weight of the
respective compound. Characteristic M +2 ion peaks with one-third intensity of
molecular ion peak were observed in case of compounds having chlorine
atom. Fragmentation pattern can be observed to be particular for these
compounds and the characteristic peaks obtained for each compound.
Probable fragmentation pattern for DNJ-1301, DNJ-1401 and DNJ-1501 can
be discussed as under.
N'-1-(morpholin-4-ylmethyl)-2-oxo-1, 2-dihydro-3H-indol-3-ylidene]-2-
propylpentanohydrazide (DNJ-1301)
1. The target compound showed characteristic molecular ion peak.
2. C7-N4 bond cleavage gave characteristic peak at 299 m/e. [1]
3. C7-N8 bond cleavage gave two characteristic peaks at 287 m/e and 100
m/e (base peak). [2]
4. After C7-N8 bond cleavage, C27-C28 bond cleavage and subsequently
C24-C25 bond cleavage gave characteristic peaks at 272 m/e and 259
m/e respectively. [3] & [4]
5. After C27-C28 and C24-C25 bond cleavages, C26-C27 bond cleavage and
subsequently C23-C24 bond cleavage gave two characteristic peaks at
245 m/e and 216 m/e respectively. [5] & [6]
6. After C26-C27 and C23-C24 bond cleavages, C20-C22 bond cleavage and
subsequently C20-C21 bond cleavage gave two characteristic peaks at
188 m/e and 175 m/e respectively. [7] & [8]
7. After C20-C22 and C20-C21 bond cleavages, N19-C20 bond cleavage gave
characteristic peak at 160 m/e. [9]
Department of Chemistry, Saurashtra University, Rajkot – 360 005 162