REACTIONS OF 2,3,5,6-TETRAKIS(β-Hydroxyethylmercapto)-1,4-Hydroquinone AND RELATED COMPOUNDS

Abstract

The treatment of chloranil (I) with alkali and 2-mercaptoethanol resulted not only in replacement of the chlorine atoms but also in reduction to form 2,3,5,6-tetrakis(β-hydroxyethylmercapto)-1,4-hydroquinone (II). The conditions for the preparation of 2,3,5,6-tetrakis(β-chloroethylmercapto)-1,4-hydroquinone (III) from II differed from those required for the preparation of a lower-melting compound (IV) from II by such a narrow margin that exact control of temperature and concentration were necessary in order to avoid erratic behavior in the preparation. The structure of the lower-melting compound has been established as 2,3-dihydro-5,7,8-tris(β-chloroethylmercapto)-6-hydroxy-1,4-benzoxathiin (IV) by analyses and cyclization reactions. The treatment of 2,3-dichloro-1,4-naphthoquinone (VIII) with 2-mercaptoethanol yielded 2,3-bis(β-hydroxyethylmercapto)-1,4-naphthoquinone (IX) and not the quinol as was the case with chloranil. The quinone (IX) could not be converted to 2,3-bis(β-chloroethylmercapto)-1,4-naphthoquinone by treatment with hydrogen chloride because under these conditions only 1,4-oxathio-5,10-anthraquinone (X) was formed. A mechanism for the formation of X which involves intramolecular addition, elimination, and cyclization is described.

Colorless metallodithiolene oligomers and polymers with intense near- and mid-infrared absorption

“…Compounds 1-3 were synthesized according to the procedures reported in literature. [34][35][36] The synthesis and characterizations for 1-3 are given in ESI. †…”

Derivatives of 1,4‐naphthoquinone as visible‐light‐absorbing one‐component photoinitiators for radical polymerisation

“…MS (CI): m/z 338.8 ([M] + ). Compound 3, red powder, yield 0.93 g, 60%, mp 116°C (117-118°C[37]). 1 H NMR (250 MHz) in DMSO-d 6 : d 2.73-2.78 (t, J = 6.5 Hz, 2H, CH 2 CH 2 OH), 2.74-2.79 (t, J = 6.5 Hz, 2H, CH 2 CH 2 OH), 3.65-3.70 (t, J = 6.5 Hz, 2H, CH 2 CH 2 OH), 3.66-3.71 (t, J = 6.5 Hz, 2H, CH 2 CH 2 OH), 7.65-7.73 (m, 2H, 6H, 7H), 7.84-7.92 (m, 2H, 5H, 8H); MS (CI): m/z 310.8 ([M] + ).Compound 4, red powder, yield 1.37 g, 80%, mp 177°C.…”

Intense near- and mid-infrared absorbing films of electrochemically crosslinked multinuclear metallodithiolene complex polymers

“…Air-and moisture-sensitive syntheses were carried out in standard Schlenk-type glassware under argon atmosphere. Compounds 1-5 were synthesized according to the procedures reported in the literature [41][42][43][44][45] .…”

“…Accordingly, a new carbazole-containing ligand 4 was synthesized(SI-1, see the Electronic Supplementary Material of this paper) [41,42] in order to prepare electrochemically active complex 6b and polymer 7b[Scheme 1(A)]. Complex 6b and polymer 7b(n=28, as determined by ICP analysis, SI-2, see the Electronic Supplementary Material of this paper) were then prepared and fully characterized by 1 H/ 13 C/ 31 P NMR and MS ( Fig.S6 and Fig.S7, see the Electronic Supplementary Material of this paper) and elemental analysis.…”