Triethylamine → 1-Boc-4-(2,3-dihydrobenzo[b][1,4]dioxin-6-ylsulfonyl)piperazine

HRID 77431Notes

Reaction equation

HRID 77431 reaction equation
[C:1]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].C(N(CC)CC)C.[O:21]1[CH2:26][CH2:25][O:24][C:23]2[CH:27]=[C:28]([S:31](Cl)(=[O:33])=[O:32])[CH:29]=[CH:30][C:22]1=2>ClCCl>[C:1]([N:8]1[CH2:9][CH2:10][N:11]([S:31]([C:28]2[CH:29]=[CH:30][C:22]3[O:21][CH2:26][CH2:25][O:24][C:23]=3[CH:27]=2)(=[O:32])=[O:33])[CH2:12][CH2:13]1)([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 143452tert-Butyl piperazine-1-carboxylateHCID 27761692,3-Dihydro-1,4-benzodioxine-6-sulfonyl chloride

Product 1

HCID 461798821-Boc-4-(2,3-dihydrobenzo[b][1,4]dioxin-6-ylsulfonyl)piperazineYield 100.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1-Boc-piperazine (250 mg, 1.34 mmol, 1 equiv.) was dissolved in dichloromethane (2.5 mL) and cooled in an ice bath under nitrogen atmosphere. Triethylamine (375 μl, 2.68 mmol, 2.0 equiv.) was added followed by portionwise addition of 2,3-dihydrobenzo[b][1,4]dioxine-6-sulfonyl chloride (346 mg, 1.48 mmol, 1.1 equiv.). The reaction was stirred in the ice bath for one hour, then quenched with saturated aqueous ammonium chloride (˜3 mL). The organic layer was washed twice with saturated ammonium chloride, once with brine, dried over sodium sulfate and concentrated in vacuo and then purified on silica gel chromatography using a 95/5-5/95, hexane/EtOAc (v/v) gradient to give 1-boc-4-(2,3-dihydrobenzo[b][1,4]dioxin-6-ylsulfonyl)piperazine as a white powder (516 mg, 89% yield).

Workup

  1. temperaturecooled in an ice bath under nitrogen atmosphere
  2. customquenched with saturated aqueous ammonium chloride (˜3 mL)
  3. washThe organic layer was washed twice with saturated ammonium chloride, once with brine
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated in vacuo
  6. custompurified on silica gel chromatography

Sources & evidence

ORD record
ord-1bdc64ddb3a04ed993f522192a6d5c09
Source dataset
uspto-grants-2014_09
Patent number
US08841305B2

Reaction notes

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