SNAr nucleophilic substitution of 1, 9-dihalodipyrrins by S- and N- nucleophiles. Synthesis of new dipyrrins bearing pendant substituents. (June 2016)

• Record Type: Journal Article
• Authors: Leushina, Evgenia; Tikhomirova, Ksenia; Permyakova, Anastasiya; Ilin, Pavel; Terenina, Maria; Anisimov, Alexander; Khoroshutin, Andrey
• Is Part Of: Dyes and pigments. Volume 129(2016)
• Page Start: 149
• Page End: 155
• Publication Date: 2016-06
• Subjects: 1, 9-dihalo-H-dipyrrins -- Nucleophilic substitution -- S-nucleophiles -- N-nucleophiles -- UV–Vis spectra -- NMR; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2016.02.018
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: 5-Aryl-1, 9-dichlorodipyrrins react with a series of S- and N- nucleophiles (both alkyl- and aryl- ones). Reagents with mercapto group yield product of double nucleophilic substitution of 5-pheny-1, 9-dichlorodipyrrin, i.e. the respective 1, 9-bis(alkyl-of arylthio)dipyrrin. On the contrary, 5-(4-nitrophenyl)-1, 9-dichlorodipyrrin causes disulfides formation from the S-aliphatic substrates, whereas nucleophilic substitution remains the main path of the reaction for S-aryl ones. The reaction of N-Alkyl nucleophiles proceeds as mono-substitution. UV–Vis spectra feature a batochromic shift for bis-S-substituted products and a hypsochromic shift for mono-N-substituted ones, with respect to the starting dichlrorides. Graphical abstract: Highlights: Free 1, 9-dichlorodipyrrins indergo nucleophilic substitution by S- and N-nucleophiles. S-nucleophiles yield disubstitution, i.e. 1, 9-dithiadipyrrins are the products. N-nucleophiles quantitatively substitute only one chlorine atom. UV–Vis spectra of bis-S-substituted products shift bathochromically as to that of dichlorides. Mono-N-substituted products with H-bonding group feature two bands in the UV–Vis spectra.