Sodium Chloride → (2-Bromophenyl)(p-tolyl)sulfane

Temperature

120 °C

In a stirred nitrogen covered reactor N-methyl-pyrrolidone, NMP (4.5 L) was flushed with nitrogen for 20 minutes. 4-Methylbenzenethiol (900 g, 7.25 mol) was added and then 1,2-dibromobenzene (1709 g, 7.25 mol). Potassium tert-butoxide (813 g, 7.25 mol) was finally added as the last reactant. The reaction was exothermic giving a temperature rise of the reaction mixture to 70° C. The reaction mixture was then heated to 120° C. for 2-3 hours. The reaction mixture was cooled to room temperature. Ethyl acetate (4 L) was added and aqueous sodium chloride solution (15%, 2.5 L). The mixture was stirred for 20 minutes. The aqueous phase was separated and extracted with another portion of ethyl acetate (2 L). The aqueous phase was separated and the organic phases were combined and washed with sodium chloride solution (15%, 2.5 L). The organic phase was separated, dried with sodium sulphate and evaporated at reduced pressure to a red oil which contains 20-30% NMP. The oil was diluted to twice the volume with methanol and the mixture was refluxed. More methanol was added until a clear red solution was obtained. The solution was cooled slowly to room temperature while seeded. The product crystallises as off white crystals, they were isolated by filtration and washed with methanol and dried at 40° C. in a vacuum oven until constant weight.

1. customIn a stirred nitrogen covered reactor N-methyl-pyrrolidone, NMP (4.5 L) was flushed with nitrogen for 20 minutes
2. customThe reaction was exothermic giving a temperature rise of the reaction mixture to 70° C
3. temperatureThe reaction mixture was cooled to room temperature
4. customThe aqueous phase was separated
5. extractionextracted with another portion of ethyl acetate (2 L)
6. customThe aqueous phase was separated
7. washwashed with sodium chloride solution (15%, 2.5 L)
8. customThe organic phase was separated
9. dry with materialdried with sodium sulphate
10. customevaporated at reduced pressure to a red oil which
11. additionThe oil was diluted to twice the volume with methanol
12. temperaturethe mixture was refluxed
13. additionMore methanol was added until a clear red solution
14. customwas obtained
15. temperatureThe solution was cooled slowly to room temperature
16. customThe product crystallises as off white crystals
17. customthey were isolated by filtration
18. washwashed with methanol
19. customdried at 40° C. in a vacuum oven until constant weight

ORD record

ord-4396448125914307bb71603f947b7fc9

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08507526B2