Hydrochloric Acid → tert-Butyl 4-carbamothioylpiperazine-1-carboxylate

HRID 590205Notes

Reaction equation

HRID 590205 reaction equation
[N:1]1([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.Cl.O1CCOCC1.[S-:21][C:22]#[N:23]>C1COCC1.O>[NH2:23][C:22]([N:4]1[CH2:5][CH2:6][N:1]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:2][CH2:3]1)=[S:21]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 9322ThiocyanateHCID 312751,4-DioxaneHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 12093220tert-Butyl 4-carbamothioylpiperazine-1-carboxylateYield 92%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

1,1-Dimethylethyl 1-piperazinecarboxylate (24 g, 129 mmol) in THF (1 L) was treated with 4N HCl in dioxane (32.2 mL, 129 mmol)), and thiocyanate (12.52 g, 129 mmol) dissolved in minimal amount of water was added. After stirring at rt overnight, the volatiles were removed under reduced pressure. The residue was taken up in MeOH and filtered to remove inorganic salts and the solvent removed in vacuo and the cycle was repeated 3 more times. Then twice taken up in DCM and filtered and concentrated to give the title compound of Step A (29 g, 92% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 8.74 (br. s., 2H), 3.50 (br. s., 4H), 3.07 (t, J=5.0 Hz, 4H), 1.40 (s, 9H).

Workup

  1. additionwas added
  2. customthe volatiles were removed under reduced pressure
  3. filtrationfiltered
  4. customto remove inorganic salts
  5. customthe solvent removed in vacuo
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-56738b8154884af68a98abcfcf40ec2b
Source dataset
uspto-grants-2016_01
Patent number
US09233956B2

Reaction notes

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