Triethylamine → Ethyl 4-(3,4,5-trimethoxybenzoyl)piperazine-2-carboxylate

HRID 358760Notes

Reaction equation

HRID 358760 reaction equation
Cl.Cl.[NH:3]1[CH2:8][CH2:7][NH:6][CH2:5][CH:4]1[C:9]([O:11][CH2:12][CH3:13])=[O:10].C(N(CC)CC)C.[CH3:21][O:22][C:23]1[CH:24]=[C:25]([CH:29]=[C:30]([O:34][CH3:35])[C:31]=1[O:32][CH3:33])[C:26](Cl)=[O:27]>ClCCl>[CH3:35][O:34][C:30]1[CH:29]=[C:25]([CH:24]=[C:23]([O:22][CH3:21])[C:31]=1[O:32][CH3:33])[C:26]([N:6]1[CH2:7][CH2:8][NH:3][CH:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:5]1)=[O:27]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 78282Benzoyl chloride, 3,4,5-trimethoxy-HCID 11253230Ethyl Piperazine-2-carboxylate Dihydrochloride

Product 1

HCID 10360649Ethyl 4-(3,4,5-trimethoxybenzoyl)piperazine-2-carboxylateYield 88.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a mixture of ethyl piperazine-2-carboxylate dihydrochloride (2.0 g), triethylamine (1.2 ml) and dichloromethane (40 ml) is added dropwise, under ice-cooling while stirring, a solution of 3,4,5-trimethoxybenzoyl chloride (1.85 g) in dichloromethane (25 ml). The mixture is stirred for one hour, then the reaction mixture is poured into ice-water, followed by extraction with methylene chloride. The organic layer is washed with water, dried and concentrated under reduced pressure. The residue is purified by means of a silica gel column chromatography (eluent : ethyl acetate-acetone-hexane=2:1:2) to afford ethyl 4-(3,4,5-trimethoxybenzoyl)piperazine-2-carboxylate (2.5 g). This product is recrystallized from ethyl acetatehexane to give colorless crystals, m.p. 114-115° C.

Workup

  1. additionis added dropwise, under ice-
  2. temperaturecooling
  3. stirringThe mixture is stirred for one hour
  4. extractionfollowed by extraction with methylene chloride
  5. washThe organic layer is washed with water
  6. customdried
  7. concentrationconcentrated under reduced pressure
  8. customThe residue is purified by means of a silica gel column chromatography (eluent : ethyl acetate-acetone-hexane=2:1:2)

Sources & evidence

ORD record
ord-ec85f6572af341008f26cb694c5b2f6b
Source dataset
uspto-grants-1991_03
Patent number
US04997836

Reaction notes

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