Dichloromethane → 1-((3-Methylbenzo[b]thiophen-2-yl)methyl)piperazine dihydrochloride

HRID 639463Notes

Reaction equation

HRID 639463 reaction equation
[CH3:1][C:2]1[C:3]2[CH:24]=[CH:23][CH:22]=[CH:21][C:4]=2[S:5][C:6]=1[CH2:7][N:8]1[CH2:13][CH2:12][N:11](C(OC(C)(C)C)=O)[CH2:10][CH2:9]1.C(O)(C(F)(F)F)=O.C(=O)(O)[O-].[Na+].C(Cl)[Cl:38]>>[ClH:38].[ClH:38].[CH3:1][C:2]1[C:3]2[CH:24]=[CH:23][CH:22]=[CH:21][C:4]=2[S:5][C:6]=1[CH2:7][N:8]1[CH2:9][CH2:10][NH:11][CH2:12][CH2:13]1

Participants

5

Reactant 4

HCID 6344DichloromethaneHCID 6422Trifluoroacetic acidHCID 516892Sodium BicarbonateHCID 68415560t-Butyl 4-((3-methylbenzo[b]thiophen-2-yl)methyl)piperazine-1-carboxylate

Product 1

HCID 684137241-((3-Methylbenzo[b]thiophen-2-yl)methyl)piperazine dihydrochloride

Procedure

The title A compound, t-butyl 4-((3-methylbenzo[b]thiophen-2-yl)methyl)piperazine-1-carboxylate is dissolved in dry DCM (50 mL), and 5 equiv. of TFA are added at 0° C. The reaction mixture is stirred at RT for 3 h. After the solvent is evaporated in vacuo, the residue is trituated in Et2O, and the precipitate that forms is collected by filtration, washed with EtOH and dried in a vacuum oven at 40° C. overnight to give a hygroscopic solid. The solid is treated with sodium bicarbonate solution, and extracted with EtOAc. The organic layer is evaporated in vacuo, and the residue is dissolved in Et2O and treated with a solution of hydrochloric acid in Et2O. The precipitated solid is collected by filtration and dried to give 1-((3-methylbenzo[b]thiophen-2-yl)methyl)piperazine dihydrochloride: LC/MS (M+1=247.1). 1H NMR (DMSO-d6, 200 MHz) δ 2.48 (s, 3H), 3.39 (m, 4H), 3.54 (m, 4H), 4.63 (s, 2H), 7.45 (m, 2H), 7.84 (d, 1H, J=7.2 Hz), 7.95 (d, 1H, J=7.2 Hz), 9.52 (br s, NH). Anal. calculated for (C14H18N2S 2HCl): C, 52.66; H, 6.31; Cl, 22.21; N, 8.77; S, 10.04. Found: C, 52.70; H, 6.58; N, 8.77; S, 9.70.

Workup

  1. customAfter the solvent is evaporated in vacuo
  2. filtrationthe precipitate that forms is collected by filtration
  3. washwashed with EtOH
  4. customdried in a vacuum oven at 40° C. overnight
  5. customto give a hygroscopic solid
  6. extractionextracted with EtOAc
  7. customThe organic layer is evaporated in vacuo
  8. dissolutionthe residue is dissolved in Et2O
  9. additiontreated with a solution of hydrochloric acid in Et2O
  10. filtrationThe precipitated solid is collected by filtration
  11. customdried

Sources & evidence

ORD record
ord-1156e4869cd34d0f9bbdb5c24b33d4d9
Source dataset
uspto-grants-2010_04
Patent number
US07691869B2

Reaction notes

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