Phenylthioacetylene

Abstract

[6228-98-4] C8H6S (MW 134.21) InChI = 1S/C8H6S/c1-2-9-8-6-4-3-5-7-8/h1,3-7H InChIKey = KTDJFTDAVHPTDO-UHFFFAOYSA-N (synthesis of phenylthioalkynes;1 synthesis of phenyl thiolesters;1a synthesis of vinyl sulfides;1b,1d,2 synthesis of carbonyl compounds3) Physical Data: bp 48–50 °C/1.5 mmHg, 86–88 °C/14 mmHg; d 1.084 g cm−3. Solubility: sol organic solvents. Form Supplied in: pale yellow to dark brown-green liquid. Analysis of Reagent Purity: gas chromatography; 1H NMR. Preparative Methods: stepwise elimination of HBr from the dibromide obtained by bromination of Phenyl Vinyl Sulfide (eqs 1 and 2).4 (1) (2) This procedure is recommended due to problems encountered with the reproducibility of the one-pot dehydrobromination of phenylthio-1,2-dibromoethane.5 Phenylthioacetylene has also been prepared by elimination of thiophenol from cis-1,2-bis(phenylthio)ethylene,6 dehydrobromination of the cis isomer of (E)‐1‐Bromo‐2‐phenylthioethylene,7 LDA-induced double elimination of ethanol from bromoacetaldehyde diethyl acetal,8 and reaction of Lithium (Trimethylsilyl)acetylide with either phenylsulfinyl chloride9 or the relatively expensive Phenyl Benzenethiosulfonate1b,1d,10 and subsequent desilylation. Purification: distillation at reduced pressure. Handling, Storage, and Precautions: use in a fume hood; use immediately after distillation for best results (pale yellow); turns dark brown–green upon storage at −10 °C (freezer) and is stable for a few months under these conditions; methyl phenyl sulfide can act as a stabilizer, and the reagent shows no tendency to darken in its presence.6b