The Addition of p-Thiocresol to Two Conjugated Dienes

Abstract

Two grams (0.011 mole) of 6-ethoxybenzothiophene, 2.0 g. (0.026 mole) of dimethylformamide and 3.0 g. of phosphorus oxychloride were dissolved in 10 ml. of dioxane and allowed to stand at room temperature for 2 hr. The mixture was heated at 70°for 3 hr. and poured into an aqueous solution of excess sodium acetate. After the mixture had been allowed to stand overnight, the precipitate was collected and recrystallized from dilute ethanol to give 0.8 g. (34%) of light strawcolored needles melting at 99°.Anal. Caled, for CuHmChS: S, 15.52. Found: S, 15.44. 6-Ethoxybenzothiophene-S-carboxaldehyde oxime. This derivative was found to melt at 171°.

Thiyl Radicals in Organic Synthesis

“…The addition of thiols onto 1,3-dienes has been known since the early work of Posner, who reported the addition of thiophenol to 1-phenyl-1,3-butadiene . Later, the regioselectivity of the addition process was studied with other dienes, including 2,3-dimethyl-1,3-butadiene, , 1,3-butadiene, , 3-methylenecyclohexene, 1,2-dimethylenecyclohexane, 2-methyl-1,3-butadiene (isoprene), 2-chloro-1,3-butadiene, and 1,3-pentadiene (piperylene) . The addition of thiophenol generally takes place at room temperature even in the absence of any added radical initiator, albeit with a very slow reaction rate, whereas other thiols such as thiolacetic acid and alkanethiols usually do not react without thermal or photochemical activation.…”

The Main Mechanism and Cross-Linking Structure for Accelerated Sulfur Vulcanization

“…The addition of a free radical to the diene compound produces the allylic radical and results in several products of structural isomers [36][37][38][39][40][41][42][43][44][45] .…”

Organic Sulfur Compounds. VII. Some Addition and Co-oxidation Reactions of Thiols with 2,5-Dimethyl-2,4-hexadiene

“…The magnitude of the coupling constant (15)(16) c.p.s.) of the vinyl protons is characteristic of trcrnsinternal olefins.…”