Ethyl 2-thiopheneglyoxylate → [(3-Methyl-butyl)-hydrazono]-thiophen-2-yl-acetic acid ethyl ester

HRID 30977Notes

Reaction equation

HRID 30977 reaction equation
[CH2:1]([O:3][C:4](=[O:12])[C:5](=O)[C:6]1[S:7][CH:8]=[CH:9][CH:10]=1)[CH3:2].[CH3:13][CH:14]([CH3:19])[CH2:15][CH2:16][NH:17][NH2:18]>C(O)C>[CH2:1]([O:3][C:4](=[O:12])[C:5](=[N:18][NH:17][CH2:16][CH2:15][CH:14]([CH3:19])[CH3:13])[C:6]1[S:7][CH:8]=[CH:9][CH:10]=1)[CH3:2]

Participants

4

Reactant 2

HCID 77693Ethyl 2-thiopheneglyoxylateHCID 18696583(3-Methylbutyl)hydrazine

Product 1

HCID 72562995[(3-Methyl-butyl)-hydrazono]-thiophen-2-yl-acetic acid ethyl esterYield 47.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of oxo-thiophen-2-yl-acetic acid ethyl ester (1d) (3.97 g, 21.6 mmol) in absolute ethanol (100 mL), (3-Methyl-butyl)-hydrazine (2b) (2.0 g, 19.6 mmol) was added. The mixture was stirred at 80° C. under N2 atmosphere for 2-25 hours. The reaction mixture was concentrated under reduced pressure and the residue was purified by flash chromatography on silica gel to give the desired product (3d) (2.48 g) that was directly used in the next step. LC-MS (ESI+): m/e 269.2 [M+1]+, 537.4 [2M+1]+, 559.0 [2M+Na]+ (exact ms: 268.12).

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. customthe residue was purified by flash chromatography on silica gel

Sources & evidence

ORD record
ord-87f0c78e6581409aafe2d4313913c391
Source dataset
uspto-grants-2008_09
Patent number
US07425552B2

Reaction notes

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