73384-58-4

Upstream product

• 17118-70-6 (chlorocarbonyl)phenyl ketene 
• 16954-69-1 2-methylaminobenzthiazole 
• 15781-73-4 di(2,4,6-trichlorophenyl)-2-phenylmalonate 
• 97684-89-4 3-(5,6,7,8-Tetrachlor-3-hydroxy-1,4-benzodioxin-2-ylcarbonyl)benzothiazolin-2-methylimin 
• 97684-71-4 1-Methyl-4-oxo-4H-benzothiazolo<3,2-a>pyrimidin-1-ium-2-olat 

Downstream Products

• 97684-80-5 3,4-Bis(diethylamino)-2-phenyl-1H-pyrido<2,1-b>benzothiazol-1-on 
• 97684-88-3 3-Diethylamino-4-methyl-2-phenyl-1H-pyrido<2,1-b>benzothiazol-1-on 

Relevant academic research and scientific papers

Synthesis of 4-Oxo-4H-benzothiazolopyrimidin-1-ium-2-olates and their Cycloaddition Reactions to Electron-poor and Electron-rich Alkynes as well as to o-Chloranil

The synthesis and physical properties of the title compounds 3a-d, prepared from 1 and bis(2,4,6-trichlorophenyl) malonates 2a-d, are described.As cyclic 1,4-dipoles, the betaines 3 combine with dimethyl acetylenedicarboxylate, dibenzoylethylene or bis(diethylamino)ethyne with formation of primary adducts of type 4, which release methyl isocyanate to give pyridobenzothiazole derivatives 5a-g, whereas the reaction of 3a with bis(dimethylamino)ethyne yields the betaine 7.With unsymmetrically substituted alkynes like methyl propiolate or 1-(diethylamino)propyne, 3 reacts with regiospecific formation of 8a-f.On the other hand, the reaction of 3a with o-chloranil proceeds with regiospecific formation of the 1,4-benzodioxin derivative 11.In case of 8, the observed regiospecificities are in agreement with the results of MNDO calculations and MO-perturbation theory.

Reactions of (Chlorocarbonyl)phenylketene. Formation of Ring-Fused 4H-1,3-Thiazinium Betaines from Heterocyclic Thiones

The betaine anhydro-2-hydroxy-8-methyl-4-oxo-3-phenyl-4H-imidazothiazinium hydroxide, formed from 1-methyl-2(3H)-imidazolethione and (chlorocarbonyl)phenylketene, underwent thermal rearrangement (220 deg C) to 2,3-dihydro-7-hydroxy-2-methyl-5-