Synthesis of [1,3]Dithiole and Spiro[1,3]dithiole Thiopyran Derivatives of the [1,2]Dithiolo[1,4]thiazine Ring System

Abstract

We report the synthesis of some new polysulfur-nitrogen heterocycles by cycloaddition reactions to readily available tricyclic condensed 1,2-dithiole-3-thiones. Thus, treatment of bis[1,2]dithiolopyrrole ketothione 1 with diacyl acetylenes gave the bis-aducts 2a-d. On the other hand, cycloaddition of bis[1,2]dithiolo[1,4]thiazine ketothione 3 with 1 equiv of acyl or diacyl acetylenes gave [1,3]dithiolylidenyl[1,2]dithiolo[1,4]thiazines 4a-f in fair to high yields. Catalysis by scandium triflate was used in the reactions that implied the less reactive dipolarophiles. Treatment of 3 with 2 equiv of DBA gave the bis-aduct 5a, and reaction of 4c with DMAD gave the mixed bis-adduct 5b. Cyclic voltammetry of selected examples showed irreversible processes that were influenced by the electrochemical activity of peripheral groups bonded to the heterocyclic system.

Green/Yellow‐Emitting Conjugated Heterocyclic Fluorophores for Luminescent Solar Concentrators

“…1 H NMR (200 MHz, CDCl 3 ): δ = 10.03 (s, 1 H), 7.63 (d, J = 5.4 Hz, 1 H), 7.00 (d, J = 5.2 Hz, 1 H), 2.95 (t, J = 7.4 Hz, 2 H), 1.55–1.74 (m, 2 H), 1.21–1.40 (m, 6 H), 0.80–0.95 (m, 3 H) ppm. Spectroscopic data are in agreement with those reported in the literature …”

Synthesis of 6,7‐Dihydropyrrolo[2,1‐c][1,3]thiazino[3,2‐a]pyrazine‐4(11bH)‐(thi)ones from 1,2‐Dithiolo‐3‐(thi)ones

“…3H-Benzo[c] [1,2]dithiole-3-thione (1a), [18] 3H- [1,2]dithiolo [3,4-b]pyridine-3-thione (1b), [19] 4-ethyl- [1,2]dithiolo [4,3-b]indole-3(4H)-thione (1c), [20] 3-thioxoindeno-[1,2-c] [1,2]dithiol-4(3H)-one (1d), [21] 5-phenyl-3H-1,2-dithiole-3-thione (1h), [19] 4-phenyl-3H-1,2-dithiole-3-thione (1i), [22] 4-chloro-5-(pyrid-2-ylthio)-3H-1,2-dithiole-3-thione (1j), [23] 4-chloro-5-(phenylthio)-3H-1,2-dithiole-3-thione (1k), [23] 4-chloro-5-phenoxy-3H-1,2dithiole-3-thione (1l), [23] 4-chloro-5-morpholino-3H-1,2-dithiole-3thione (1m), [23] 3,4-dihydropyrrolo[1,2-a]pyrazine (2), [24] 3Hbenzo[c][1,2]-dithiol-3-one (8a), [25] 3H- [1,2]dithiolo [3,4-b]pyridine-3one (8b), [26] 5-phenyl-3H-1,2-dithiole-3-one (8c), [26] (15), [18a] N-methyl-1-phenylmethanimine (17) [27] were prepared according to the published methods and characterized by NMR spectra. The reagents were purchased from commercial sources and used as received.…”

“…[15] As such, compound 11 was treated with DMAD (1 equiv.) [17] These chains align in slipped stacks where each alternating chain is composed of molecules with the same chirality. ), to give the 1,3-dithiole 13 in 73 % yield (Scheme 3).…”

Heterocyclic Chemistry of Sulfur Chlorides – Fast Ways to Complex Heterocycles

“…Scheme 13. The sulfur atom of the 1,4-thiazine ring was easily extruded in all the N-substituted di [1,2]dithiolo- [1,4]thiazine derivatives (but not in the N-unsubstituted) yielding pyrrole derivatives 51-53 (Scheme 14). [20,22] Dithiolthiones reacted as either dienophile [23] or dipolarophile [24] reagents in 1,3-dipolar cycloadditions, show-…”

“…The initial 1,3-dipolar cycloaddition of di-dithiolo-thiazines), or di-dithiolo-pyrroles, and typical dipolarophiles generated heterodynes of type 54 that were the substrate of subsequent hetero-Diels-Alder cycloadditions to give 55 (Scheme 15). [23] Scheme 15.…”