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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: GinaTageldin on March 17, 2020, 07:27:41 AM

Title: Mechanism for replacement of SCH3 by OH using 2-mercaptoethanol?
Post by: GinaTageldin on March 17, 2020, 07:27:41 AM

i have 4-aryl-1-methyl-2-methylsulfanyl-6-oxo-1,6-dihydropyrimidine-5-carbonitrile derivative
and i reacted it with 2-mercaptoethanol in dichloromethane and DIPEA at room temperature for 14 h, the resulted product revealed removal of the methylsulfanyl moiety and introduction of a OH group?
Also i reacted the same compound with oxone and yielded the same product? Any explanation for the mechanism using 2-mercaptoethanol

Title: Re: Mechanism for replacement of SCH3 by OH using 2-mercaptoethanol?
Post by: pgk on March 18, 2020, 01:52:31 PM

Think about a DIPEA catalyzed, thiirane formation that liberates a hydroxyl anion, which attacks to the 2 position and liberates the methylsulfanyl group. The transition intermediate is stabilized by conjugation with the nitrile group, through the unsaturated ring.