Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Infrared (GC-IR) Analyses of the Chloro-1-n-pentyl-3-(1-naphthoyl)-Indoles: Regioisomeric Cannabinoids

• NCJ Number: 254135
• Journal: Applied Spectroscopy Volume: 73 Issue: 4 Dated: 2019 Pages: 433-443
• Author(s): Karim M. Abdel-Hay; Tarek S. Belal; Younis Abiedalla; Amber Thaxton-Weissenfluh; Jack DeRuiter; Forrest Smith; C. Randall Clark
• Date Published: 2019
• Length: 11 pages
• Grant Number(s): 2005-IJ-CX-K140
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored); Program/Project Description

Annotation

This article describes the analytical differentiation of the indole ring regioisomeric chloro-1-n-pentyl-3-(1-naphthoyl)-indoles.

Abstract

The regioisomeric chloroindole precursor compounds, N-n-pentyl chloroindole synthetic intermediates, and the target chloro-substituted naphthoylindoles showed the equivalent gas chromatographic elution order based on the position of chlorine substitution on the indole ring. The regioisomeric chloro-1-n-pentyl-3-(1-naphthoyl)-indoles yield electron ionization mass spectra having equivalent major fragments resulting from cleavage of the groups attached to the central indole nucleus. Fragment ions occur at m/z 127 and 155 for the naphthyl and naphthoyl cations common to all indoles having the naphthoyl group substituted at the indole-3 position. Fragments resulting from the loss of the naphthoyl and/or n-pentyl groups from the molecular radical cation yield the cations at m/z 318, 304, 248, and 178. The characteristic (M-17)+ fragment ion at m/z 358 resulting from the loss of OH radical is significant in the mass spectra of all these compounds with 1-naphthoyl groups substituted at the indole-3 position. The vapor phase infrared spectra provide a number of characteristic absorption bands to identify the individual isomers. (publisher abstract modified)