In this paper, the side reactions in the reaction of lauryl chloride (RCl) with sodium hydrogensulfide (NaSH) in a protic solvent,
n-butanol (
n-BuOH), and a dipolar aprotic solvent, dimethylformamide (DMF), were mainly investigated.
The absorbances of 425 and 620mμ of electronic spectrum of NaSH-DMF solution decreased proportionally with added amount of water in this solution. Moreover, from other spectroscopic results, namely the increase in absorbance with concentrations of NaSH or the dependence of absorbance on time, and the synthetic results in
n-BuOH and DMF, the presence of solvated complexes, for instance, HS
-…DMF and HS
-…DMF…Na
+ was implied.
It was clear that the following reactions occur more easily in
n-BuOH, than in DMF :
RCl+Na
2S→RSNa+NaCl [1a]
RSH+NaSH_??_RSNa+H
2S [1b]
RSH+NaOH_??_RSNa+H
2O [1c]
RSNa+RCl→RSR+NaCl [2]
The formation of RSR followed by reactions [1c] and [2] is almost quantitative in
n-BuOH. These experimental results were well explained in terms of the difference in solvation power of each solvent for Na
+.
In DMF, lauryl chloride reacted with sodium sulfide to yield RSH and a small amount of disulfide (RSSR). It was confirmed that the following reaction occurred :
_??_
As a cause of disulfide formation, the oxidation reaction of mercaptan in the presence of dimethylamine was examined.
View full abstract