Ethyl 3-(thiophen-2-yl)piperazine-1-carboxylate → 1-Methyl-3-(thiophen-2-yl)piperazine

HRID 462416Notes

Reaction equation

HRID 462416 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH:6]1[NH:11][CH2:10][CH2:9][N:8]([C:12](OCC)=O)[CH2:7]1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>C(OCC)C>[CH3:12][N:8]1[CH2:9][CH2:10][NH:11][CH:6]([C:2]2[S:1][CH:5]=[CH:4][CH:3]=2)[CH2:7]1

Participants

4

Reactant 2

HCID 2771741Ethyl 3-(thiophen-2-yl)piperazine-1-carboxylateHCID 21226445Aluminium lithium hydride

Product 1

HCID 130481861-Methyl-3-(thiophen-2-yl)piperazine

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of ethyl 3-(2-thienyl)piperazine-carboxylate (27.2 g, 0.11 mol; Preparation 2) in diethyl ether (300 ml) is added to a stirred suspension of lithium aluminum hydride (10.8 g, 0.28 mol) in diethyl ether (1300 ml). The mixture is refluxed for 12 h, cooled to room temperature and worked up as described in "Reagents for Organic Synthesis" , Fieser, L. F. and Fieser, M., John Wiley and Sons, Inc., New York, N.Y. 1967, p. 583. The ether solution is dried (potassium carbonate) and evaporated to give 1-methyl-3-(2-thienyl)piperazine as a light yellow oil, which is characterized as the maleate salt (m.p. 123°-124.5° C.), which is prepared in the manner described in Preparation 2.

Workup

  1. temperatureThe mixture is refluxed for 12 h
  2. customas described in "Reagents for Organic Synthesis" , Fieser, L
  3. dry with materialThe ether solution is dried (potassium carbonate)
  4. customevaporated

Sources & evidence

ORD record
ord-0463835542f8453ea4640b1ef8cf8d9f
Source dataset
uspto-grants-1985_05
Patent number
US04515792

Reaction notes

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