ChemInform Abstract: SYNTHESIS AND REACTIONS OF 2,5‐DIHYDROXY‐3,4,6,7‐TETRACHLOROCOUMARAN

Abstract

Behandeln des Trichlorbenzochinons (I) mit HCl führt zu dem Tetrachlorcumaran (II), dessen Struktur aus 1H‐ und 13C‐NMR‐Daten hervorgeht.

The structure of 2-phenylazo-5-(trichloro-1,4-benzoquinonyl)-thiazole

“…In previous work [3], we showed that the synthesis of 4H-1,3,4-thidiazines is often complicated by the formation of cyclization sideproducts though we were unable to correlate the formation of any of these products with the structure of the starting compounds.…”

“…Dihydrobenzofuran 1 is the cyclic form of the o-hydroxyphenyl derivative of α-chloroacetaldehyde [3,4]. The major products of the reactions between 1-substituted thiosemicarbazides and α-halocarbonyl compounds are derivatives of 4H-1,3,4-thiadiazine [5].…”

Methods for the Synthesis of Heteroaryl-substituted 1,4-Benzo- and 1,4-Naphthoquinones. (Review)

“…Here, during construction of the heterocycle 2,5-dihydroxy-3,4,6,7-tetrachloro-2,3-dihydrobenzo[b]furan 73 is used as universal synthon (the 2,3-trans configuration predominates). This is the cyclic tautomeric form of the aryl-substituted α-chloroacetaldehyde and is formed in the reaction of vinylquinone 72 with HCl in dioxane solution [78]. The heterocycle was constructed by the reaction of benzofuran 73 with bifunctional nucleophilic reagents.…”