Diisopropylethylamine → 1-[4-(Trifluoromethoxy)benzenesulfonyl]piperazine

To a solution of 1,1-dimethylethyl 1-piperazinecarboxylate (5 g, 26.8 mmol) in DCM (200 ml) was added DIPEA (9.85 ml, 56.4 mmol) and then 4-[(trifluoromethyl)oxy]benzenesulfonyl chloride (4.55 ml, 26.8 mmol). The reaction mixture was stirred for 1.5 hours at rt. The reaction mixture was then evaporated to dryness in vacuo. The residue was then dissolved in 1,4-dioxane (100 ml) and 4M HCl in 1,4-dioxane (50 ml) was added, along with a few drops of distilled water. The reaction mixture was stirred for 3 hrs. Then the reaction mixture was evaporated to dryness in vacuo. The residue was dissolved in DCM (200 ml) and washed with 2M aq. NaOH (50 ml, twice). The organic layer was dried over anhydrous magnesium sulphate, the solid removed by filtration, and filtrate evaporated to dryness in vacuo. The residue was not a solid so was dissolved in ether and evaporated in vacuo to remove any remaining solvent. The title compound (8.02 g) was obtained as a pale yellow solid.

1. customThe reaction mixture was then evaporated to dryness in vacuo
2. dissolutionThe residue was then dissolved in 1,4-dioxane (100 ml)
3. addition4M HCl in 1,4-dioxane (50 ml) was added, along with a few drops of distilled water
4. stirringThe reaction mixture was stirred for 3 hrs
5. customThen the reaction mixture was evaporated to dryness in vacuo
6. dissolutionThe residue was dissolved in DCM (200 ml)
7. washwashed with 2M aq. NaOH (50 ml
8. dry with materialThe organic layer was dried over anhydrous magnesium sulphate
9. customthe solid removed by filtration, and filtrate
10. customevaporated to dryness in vacuo
11. dissolutionso was dissolved in ether
12. customevaporated in vacuo
13. customto remove any remaining solvent

ORD record

ord-8f0b47baf60e48c2a58c30ed6f50c9f5

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08093249B2