Synthesis of 6‐ and 7‐Acyl‐4H‐benzothiazin‐3‐ones.

Abstract

Synthesis of 6-and 7-Acyl-4H-benzothiazin-3-ones. -Direct acylation of benzothiazinones (I) provides access towards the 7-acyl derivatives (III). In contrast, the acylation at position 6 is smoothly achieved by Stille coupling of the corresponding tributyltin derivative (VI). -(CARATO*, P.; MOUSSAVI, Z.; SABAOUNI, A.; LEBEGUE, N.; BERTHELOT, P.; YOUS, S.; Tetrahedron 62 (2006) 38, 9054-9058; Lab. Chim. Ther., Fac. Sci. Pharm. Biol., F-59006 Lille, Fr.; Eng.) -Mischke 52-171

6-Sulfonylbenzothiazolones as potential scaffolds for the design of 5-HT6 ligands

“…In the first method, benzothiazolone 1 was brominated in CHCl 3 with Br 2 to afford the corresponding 6-bromobenzothiazolone 2 [27], with good yield (85%), which was allowed to react in DMF with potassium carbonate [28] and the corresponding 2-chloroethylalkylamine derivatives to yield the Nsubstituted compounds 3e4. The Stille reaction [29,30] was then performed in two steps to furnish final compounds. Reaction in dry toluene under inert atmosphere with tetrakis(triphenylphosphine) palladium and hexabutylditin provided the expected tributyltin intermediates.…”

Development of tag-free photoprobes for studies aimed at identifying the target of novel Group A Streptococcus antivirulence agents

“…Synthesis of the benzophenone-based probes ( 10a–b , Scheme 2) began with the LDA-promoted Michael addition of 4-bromo-2-methylbenzonitrile ( 5 ) to ethyl 3,3-dimethyl acrylate and subsequent ZnI 2 -mediated cyclization to afford β-aminoester 6 . 25 Stannylation via halogen-metal exchange 26 followed by carbonylative Stille coupling 27 successfully delivered benzophenone 8 . Acid-catalyzed addition of the amine to allyl isothiocyanate and subsequent cyclization generated 2-thioxopyrimidinone 9 that underwent S -alkylation with propargyl bromide or 12 (generated via tosylation of commercially available propynol ethoxylate 11 ) under mildly basic conditions to generate probes 10a and 10b .…”