An odorless and efficient synthesis of symmetrical thioethers using organic halides and thiourea in Triton X10 aqueous micelles

Figures & data

short-legendScheme 1. Synthesis of benzyl thioether using benzyl chloride and thiourea in TX10 aqueous micelles.

Table 1. Optimization of the reaction conditions.

Entry	Time (h)	Base	Reaction medium (5 mL)	Yield (%)
1	2	Na2CO3	10 wt% TX10/H2O	54
2	2	NEt3	10 wt% TX10/H2O	45
3	2	NaOH	10 wt% TX10/H2O	87
4	2	NaOH	10 wt% SDS/H2O	67
5	2	NaOH	10 wt% CTAB/H2O	88
6	2	NaOH	H2O	63
7^a	18	NaOH	10 wt% TX10/H2O	98
8^a	18	NaOH	H2O	Trace
Note: Reaction condition: benzyl chloride 2 mmol, thiourea 2 mmol, base 3 mmol, 30 °C.
The yields were calculated form GC results.
^aReaction condition: n-heptyl iodide 2 mmol, thiourea 2 mmol, NaOH 3 mmol, 50 °C.

Figure 1.  The influence of TX10's concentration in aqueous micelles on the reaction. Reaction condition: benzyl chloride 2 mmol, thiourea 2 mmol, NaOH 3 mmol, reaction medium 5 mL, 30 °C, 2 h.

Table 2. Synthesis of symmetrical thioethers in TX10 aqueous micelles.

Entry	Time (h)	Organic halide	Temp (°C)	Product	Yield (%)^a
1	2	Benzyl iodide	30	(PhCH2)2S	96
2	2	Benzyl bromide	30	(PhCH2)2S	91
3	4	Benzyl chloride	30	(PhCH2)2S	93
4	4	4-Methylbenzyl chloride	30	(4 CH3C6H4CH2)2S	90
5	24	4-Nitrobenzyl chloride	50	(4 O2NC6H4CH2)2S	86
6	4	Allyl bromide	30	(CH2=CHCH2)2S	92
7	6	Allyl chloride	30	(CH2=CHCH2)2S	87
8	18	n-Heptyl iodide	50	(n-C7H15)2S	90
9	10	n-Butyl bromide	50	(n-C4H9)2S	92
10	12	n-Pentyl bromide	50	(n-C5H11)2S	91
11	18	n-Hexyl bromide	50	(n-C6H13)2S	87
12	24	n-Heptyl bromide	50	(n-C7H15)2S	89
13	24	n-Octyl bromide	50	(n-C8H17)2S	82
14	30	n-Decyl bromide	50	(n-C10H21)2S	70
15	24	Iso-propyl bromide	50	–	–
16	24	Cyclohexyl bromide	50	–	–
17	48	Iodobenzene	80	–	–
18	48	Bromobenzene	80	–	–
19	48	Chlorobenzene	80	–	–
20^b	4	Benzyl chloride	30	(PhCH2)2S	89
Note: Reaction condition: organic halide 2 mmol, thiourea 2 mmol, NaOH 3 mmol, 10 wt% TX10/H2O 5mL.
^aIsolated yield of product.
^bReaction condition: benzyl chloride 100 mmol, thiourea 100 mmol, NaOH 150 mmol, 10 wt% TX10/H2O 250 mL.

short-legendScheme 2. Synthesis of thioethers using iodobenzene, benzyl chloride, and thiourea in TX10 aqueous micelles.