74642-18-5

Upstream product

• 18206-22-9 bis[2-(N,N-dimethylamino)phenyl] disulfide 
• 100-52-7 benzaldehyde 
• 107647-26-7 sulfure de (dimethylamino-2) phenyle et de (methyl-3 buten-3 yn-1) yle 
• 109-72-8 n-butyllithium 

Relevant academic research and scientific papers

Synthese de sulfures et dithioacetals alleniques et leurs transformations en composes carbonyles α,β-insatures

The nucleophilic addition of various organo-lithium compounds to 1-methylthio- (or 1-phenylthio)-3-methyl-3-buten-1-yne 3 in ether affords α-lithiated allenic sulfides 4 which on protonation give 1-methylthio-3-methyl-1,2-alkadienes.These allenic sulfides can be hydrolysed into the corresponding α,β-unsaturated aldehydes by use of cupric salts in aqueous acetone.Treatment of the lithio-derivative 4aa with methyl iodide, followed by mercuric chloride in aqueous acetonitrile, yields the α,β-unsaturated methyl ketone 14 (R2=n.C4H9; R=CH3).Treatment of the lithio-derivatives 4 with methyl disulfide affords allenic dithio-acetals, which are readily hydrolysed into the corresponding methyl α,β-unsaturated esters by use of cupric salts in methanol.

Alkylation of Benzothiazolines and the Stevens Rearrangement of the Resulting 2,3,3-Trisubstituted Benzothiazolinium Salts

Alkylation of 2-substituted 3-methyl- or 3-ethylbenzothiazolines with Meerwein reagents gave 2-substituted 3,3-dialkylbenzothiazolinium tetrafluoroborates (3).The configuration of two alkyl groups on the nitrogen was assigned by NMR spectra and NOE measurement.In the Stevens rearrangement of 3 with lithium diisopropylamide ethyl group showed a much larger migratory aptitude (Et:Me>20:1) than methyl group irrespective of the configuration of 3, and cyclic ammonium ylide with planar ?-type carbanion was proposed as an intermediate. 3 suffered nucleophilic attack at the ring sulfur atom by butyllithium to afford a ring-opened ammonium ylide, which collapses to a radical pair to give unusual Stevens rearrangement product, where o-alkylthiophenyl group migrated selectively in preference to alkyl group, because of stabilization by participation of o-alkylthio group.