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

HRID 462415ノート

反応式

HRID 462415 の反応式
Cl[C:2]([O:4][CH2:5][CH3:6])=[O:3].[S:7]1[CH:11]=[CH:10][CH:9]=[C:8]1[CH:12]1[CH2:17][NH:16][CH2:15][CH2:14][NH:13]1.[OH-].[Na+]>C(O)(=O)C>[S:7]1[CH:11]=[CH:10][CH:9]=[C:8]1[CH:12]1[NH:13][CH2:14][CH2:15][N:16]([C:2]([O:4][CH2:5][CH3:6])=[O:3])[CH2:17]1

参加物

5

反応物 3

HCID 10928Ethyl chloroformateHCID 14798Sodium HydroxideHCID 27717262-Thiophen-2-yl-piperazine

生成物 1

HCID 2771741Ethyl 3-(thiophen-2-yl)piperazine-1-carboxylate収率 65.7%

試薬・触媒・溶媒 1

HCID 176Acetic Acid溶媒2 回

実験手順

A solution of ethyl chloroformate (20.4 g, 0.19 mol) in acetic acid (150 ml) is added dropwise with stirring to a solution of 2-(2-thienyl)-piperazine (31.6 g, 0.19 mol; Preparation 1) in acetic acid (150 ml) at 65° C. under an atmosphere of dry nitrogen. After 1 h, the solution is allowed to cool to room temperature, and stirring is maintained for an additional 16 h. The reaction mixture is added to chilled 10N NaOH (750 ml) and ice is added to control the exothermic reaction. The mixture is extracted with methylene chloride (4×300 ml), the organic solution is dried(potassium carbonate), and the solvent removed under reduced pressure to give the carbamate (30.0 g) as a light brown oil. This material is dissolved in methanol (250 ml), and the solution added to a solution of maleic acid (18.6 g; 1 eq) in methanol (250 ml). The mixture is treated with charcoal and the solvent removed under reduced pressure to give an oil which crystallizes on trituration with ethyl acetate. The maleate salt melts at 165°-166° C.

後処理

  1. temperatureis maintained for an additional 16 h
  2. additionThe reaction mixture is added
  3. additionis added
  4. customthe exothermic reaction
  5. extractionThe mixture is extracted with methylene chloride (4×300 ml)
  6. customthe solvent removed under reduced pressure

出典と根拠

ORDレコード
ord-29f1c506b9c94c22a2803c09e96c29c5
出典データセット
uspto-grants-1985_05
特許番号
US04515792

反応ノート

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