Mercury methide

The slight solubility of yellow phosphorus in several other liquids has been notioed— e.g. ethyl chloride, ethylene chloride, chloroform, bromoform, ohloral, acetic ether, acetone aldehyde, cacodyl sulphide, allyl thiooyanate, mercury methide, valerianic acid, amyl valerate, fusel oil, benzoyl chloride, stannic chloride, ethyl nitrite, nicotine, coniine, cavutchin, styrene, aniline, quinoline, creosote, etc. J. Hartmann found that 100 grms. of bile at 38-5° dissolved 0 02424 grm. of phosphorus, and more at a higher temp. 

As a final example we would like to note the reactions of quinone methide 27, which remains unchanged upon irradiation in methanol solution through a Pyrex or Vycor filter.128 Reduction is observed when 27 is irradiated in isopropyl alcohol with benzophenone or acetophenone,129 in methanol with acetophenone, or in methanol with no sensitizer through quartz.128 While the effect of ketone sensitizers is due to chemical sensitization,129 the wavelength effect is much more surprising. Further investigation showed that irradiation of methanol alone in a quartz vessel yielded ethylene glycol. The 185 nm line of the mercury arc, which is absorbed by Vycor and Pyrex, decomposes... 

To a quartz cuvette fitted with a Teflon stopcock was added 53 mg 2,6-dichloro-benzoquinone and 63 mg phenyl m-xylyl acetylene in CH2CI2 in a 0.1 M solution of each substance under argon. The cuvette was then placed in a clear Dewar flask filled with water at 25°C and irradiated with focused light from a medium-pressure mercury lamp (500 W) passed through an aqueous IR filter and an ESCO 410 nm filter. This ensured that the quinone itself was excited and not the diarylacetylene. After 22 h, the solvent was evaporated, and the residue was subjected to flash chromatography. 1-(3,5-Dimethylphenyl)-l-benzoyl-1-methylene-3,5-dichlorocyclohexa-2,5-dien-4-one was obtained as the major product, which was further recrystallized from acetonitrile, m.p., 191-192°C. The minor product was identified only by GC/MS. The total yield of quinone methide was 88% based on 62% of conversion. 

Iodide ion-initiated decomposition of the mercurials (13) proceeds faster with X = CF3 than with X = F. The fluorobis(trifluoromethyl)methide ion intermediate is less stable than tris(trifluoromethyl)methide (68). The efficiency of dichlorocarbene interception by various anions has been compared (69) and these fall into the anticipated sequence I Br > Cl F, NOf, ClOf. However, F is more reactive than Cl toward difluorocarbene (70). 

In 2011, Popik and co-workers reported photochemical dehydration of 3-hydroxy-2-naphthalenemethanol (o-naphthoquinone precursor, NQMP, 79) derivatives to o-naphthoquinone methides (oNQMs, 80) [78, 79]. The in situ generated reactive intermediate oNQM underwent facile cycloaddition with vinyl ethers (81) to form photostable benzochromans (82) (Scheme 12). NQMP (79) has two major absorption bands at 275 nm (log s = 4.06) and 324 nm (log s — 3.70) thus it can be photoactivated with either low pressure mercury lamp (254 nm) or fluorescent tubes (300 and 350 nm). The quantum yield of the photoactivation was very high (< 300 = 0.17 0.02 for 79). The in situ generated oNQMs was quenched mostly by... 

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