Sciencemadness Discussion Board

chlorination of in the middle hydric toluene

hydrargirum - 3-7-2005 at 18:49

In relation to the chlorination in situ of in the middle hydric toluene I want to raise the following reactions

C6H6CH3 + NaClO + HCl = C6H6CH2Cl + NaCl +H2O

C6H6CH3 + 2NaClO + 2HCl = C6H6CHCl2 + 2NaCl +2H2O

C6H6CH3 + 3NaClO +3HCl = C6H6CCl3 + 3NaCl +3H2O

It is possible that these reactions happen using NaClO in solution to 10% and
adding HCl diluted with good agitation?

hydrargirum - 9-7-2005 at 19:42

I have doing reference to the following experience that I practiced, years ago.:
I mixed in a big flask a solution of NaClO to 10% and toluene in excess and I added HCl diluted (< 10%) from a separatory funnel in slow dripping and with agitation vigorous constant and to the by day indirect light (shade). The mixture is warmed up spontaneously in form moderate and when it is had added sufficient HCl it is observed that the superior layer of toluene begins a to lower and is located in the inferior layer. Soon I separated the inferior layer
It is dried with anhydrous CaCl2 and one first fraction of toluene is distilled in fractionating column and then obtaining benzyl chloride and being left a tail of boiling point superior to 185ºC (probably bi and trichloride and others).
C6H5CH3 + NaClO + HCl -------> C6H5CH2Cl +H2O + NaCl
An excess of toluene was used > of 50% to diminish the polychlorides derivatives. A yield of around 60% was obtained ,
less the excess of toluene.I want to notice that the reaction took place under tenuous light leaving the impression that outside independent of the light?
I do not have experiences with the use of greater amounts equimolar of NaClO and HCl that would probably take to the formation of benzyl bi and trichloride

Polverone - 10-7-2005 at 01:04

The method you described has apparently been patented; it has been mentioned before here.

http://www.sciencemadness.org/talk/viewthread.php?tid=1751&a...
Quote:
Cold , Wet Sidechain chlorination

This is the simplest route to benzyl chloride Ive found so-far.


PATENT NO.GB134250

Abstract:
4,250. Levinstein, Ltd., Levinstein, H., and Bader, W. July 27, 1918. Chlorhydrocarbons. - Benzyl chloride, benzal chloride, and similar side-chain chlor-substituted aromatic hydrocarbons are prepared by treating toluene or its homologues at a low temperature with aqueous hypochlorous acid (hypochlorite and acid). The process can also be applied to the treatment of the chlor-derivatives of these hvdro- carbons containing one or two chlorine atoms in the nucleus or one chlorine atom in the side chain, e.g. monochlortoluenes, 2 : 4-dichlorto- luene, or benzyl chloride. Examples are given of the preparation of benzyl chloride from toluene and benzal chloride from benzyl chloride; m- xylene gives m-tolyl chloride and m-tolal chloride

Obviously Benzyl/benzal;chloride mixtures can be obtained by increasing the amount of hypochlorite.

Calcium hypochlorite works.

HCL works fine.

Strong mixing seems to help somewhat.

Slow addition of acid.

Can I link this patent directly?sorry.

Hope this helps.

apatzingan - 3-2-2006 at 09:19

perhaps you've seen this before: benzyl alcohol can be stirred with hydrochloric acid at STP to give benzyl chloride in high yields. Use molar excess (1:1.5 works fine) of acid and stir time can be shortened if heated. Distill to yield irritating (to skin) substance.