Chlorine propyne

CH3C C.C1. It was obtd in small quantity, mixed with ethyl bromide, by interaction of p-toluenesulfonyl chloride with methylacetylene -magnesium bromide in dibutyl ether. It was not purified. The pure compd, bp 32.8-33°, nD 1.4131 at 20°,. was prepd by dehydrohalogenation of cis -1,2-dichloro-l-propene or by chlorination of 1 -propyne (Ref 3)... 

Also, this scheme can be easily restructured using free radical intermediates on the grounds that a single electron transfer occurs instead of the more familiar two-electron transfer described here. This option may also be disregarded, however, if one takes into consideration the exclusive formation of alkynes from the free radical chlorination of propyne and allene." ... 

QUECKSILBER (German) (7439-97-6) Violent reaction with alkali metals, aluminum, acetylenic compounds, azides, boron phosphodi iodide (vapor explodes), bromine, 3-bromo-propyne, chlorine, chlorine dioxide, ethylene oxide, lithium, metals, methyl silane (when shaken in air), nitromethane, peroxyformic acid, potassium, propargyl hromide, rubidium, sodium, sodium carbide. Forms sensitive explosive products with acetylene, ammonia (anhydrous), chlorine, picric acid. Increases the explosive sensitivity of methyl azide. Mixtures with hot sulfuric acid can be explosive. Incompatible with calcium, sodium acetylide, nitric acid. Reacts with copper, silver, and many other metals (except iron), forming amalgams. 

Medvedeva et al. first investigated the substituted propynals 303 as aldehyde substrates involved MBH reactions. The initial attempt to conduct the MBH reaction in the presence of TiCU was unsuccessful because of oligomerization of the reaction mixture. However, promotion with TiCU and a catalytic amount of dimethyl sulfide in the chalcogeno-MBH reaction led to 2-[(Z, )-chloromethylidene]-3-hydroxy-1 -phenyl-5-organylpent-4-yn-1 -ones 304 by tandem a-hydroxyethynylation/p-chlorination of l-phenylprop-2-yn-l-one (Scheme 2.166). ... 

It makes a nice problem to figure out which way the second addition of HX should go. As always in a mechanistic problem of this sort, the answer only appears through an analysis of the possible pathways for further reaction. Draw out both mechanisms, compare them at every point, and search each step for differences. We will use the reaction of propyne with hydrogen chloride as a prototypal example. The initial product is 2-chloropropene, as shown in Figure 10.66. There are two possible ions from the reaction of this vinyl halide with additional hydrogen chloride. Structure A in Figure 10.67 has the positive charge adjacent to a chlorine, but structure B does not. 

How many molecules of chlorine, CI2, can be added to a molecule of 1-propene a molecule of 1-propyne ... 

METHYL ACETYLENE C.H. Propyne. Allylene Strong oxMizcrs, chlorine, copper, copper alloys NA 1.7 11.7... 

The dichlorodithionitronium cation C1SNSC1+ also serves as a masked SNS+ species because it undergoes cycloaddition reactions with alkynes and olefins. For example, reaction of the dichlorodithionitronium salt with ethyne and propyne in sulfur dioxide below room temperature affords the expected [3+2] cycloadducts 100. Most likely, an intermediate dichloro cycloadduct 99 is formed, which loses chlorine to form the isolated cycloadduct. 

The reaction of C1SNSC1+ AsFg with ethyne and propyne in sulfur dioxide affords the expected 1,3,2-dithiazolium salts in quantitative yields. The generated chlorine reacts with the sulfur dioxide to give SO2CI2... 

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