Chemical constitution and anthelmintic activity. II. Preparation of some analogues of Phenothiazine

Abstract

A convenient synthesis of 2,3-dihydrobenzo-1,4-thiazine has been developed, and the preparation of a number of substituted diphenylamines, phenothiazines, and phenoselenazines is described.

Synthesis and Electronic Properties of Alkynylated Phenothiazines

“…Alternatively, we have also applied the Sonogashira ethynylation18 with piperidine as a base to mono‐ and dibromo phenothiazines 4 19,20 to furnish, after subsequent alkaline desilylation, the desired alkynylated derivatives 1 and 2 in one pot and in good yield (Scheme , Method C). Furthermore, the application of this cross‐coupling reaction is highly compatible with the presence of fragile, base‐sensitive functional groups such as aldehydes (compounds 1d and 1e ).…”

“…Dichloromethane, diisopropylamine, dioxane, methanol, piperidine, THF, toluene, and triethylamine were dried and distilled according to standard procedures 31. The phenothiazine aldehydes 3a , 3b ,13 3e , and 4e ,11b dialdehydes 3c and 3d ,14 phenothiazine bromides 4a and 4b ,19 and dibromide 4c ,20 dimethyl 1‐diazo‐2‐oxopropylphosphonate,17 3,7‐diiodo‐ N ‐hexylphenothiazine ( 10 ),32 and 1,3,5‐triiodobenzene ( 11 )33 were prepared according to literature procedures. Column chromatography: silica gel 60 (Merck, Darmstadt), mesh 70−230.…”

Synthesis and Electronic Properties of Monodisperse Oligophenothiazines

“…The residual brown oil was chromatographed on silica gel (hexane) to give 1 (21.0 g, 98 %) as a light yellow oil. 3-Bromo-10-hexyl-10H-phenothiazine (2): [39] In an oven-dried Schlenk flask (500 mL), potassium tert-butoxide (4.50 g, 40.0 mmol) was suspended in dry THF (150 mL) and the suspension was cooled to À78 8C (acetone/dry ice bath). Then, 3-bromo-10 H-phenothiazine (10.0 g, 35.9 mmol) dissolved in dry THF (50 mL) was slowly added dropwise to the reaction mixture.…”

Structural and Spectral Analyses of 2-[(2-Benzothiazolylmethyl)thio]-benzenamine and 2-[(2-Benzothiazolylmethyl)thio]-benzenamine hydrobromide

“…The synthesis of 2-[(2-benzothiazolylmethyl)thio]-benzenamine was previously reported, but full characterization utilizing today’s technology was impossible at that time [1, 2]. After inadvertently preparing this compound, the analysis herein provides the necessary data for identification.…”

“…Further analysis of this compound was reported by Cymerman-Craig, et al as a potential anti-parasitic agent that would expel parasitic worms from mice [2]. Both Unger and Cymerman-Craig cited the melting point (89–90 °C) and elemental analysis as characterization of 2-[(2-benzothiazolylmethyl)thio]-benzenamine.…”