3-Thiophenacetic acid → Ethyl 5-[(thiophen-3-yl)methyl]-1,2,4-oxadiazole-3-carboxylate

HRID 58598

Reaction equation

HRID 58598 reaction equation
[S:1]1[CH:5]=[CH:4][C:3]([CH2:6][C:7]([OH:9])=O)=[CH:2]1.C(Cl)(=O)C(Cl)=O.[NH2:16][C:17](=[N:23]O)[C:18]([O:20][CH2:21][CH3:22])=[O:19].C(N(CC)C(C)C)(C)C>ClCCl.N1C=CC=CC=1.CN(C=O)C>[S:1]1[CH:5]=[CH:4][C:3]([CH2:6][C:7]2[O:9][N:23]=[C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[N:16]=2)=[CH:2]1

Participants

8

Reactant 4

HCID 234043-Thiophenacetic acidHCID 65578Oxalyl chlorideHCID 81531DiisopropylethylamineHCID 6785548Ethyl 2-amino-2-(hydroxyimino)acetate

Product 1

HCID 63382666Ethyl 5-[(thiophen-3-yl)methyl]-1,2,4-oxadiazole-3-carboxylateYield 38.1%

Reagents, catalysts & solvents 3

HCID 1049PyridineSolventHCID 6228DimethylformamideSolventHCID 6344DichloromethaneSolvent2×

Procedure

This compound was prepared according to general method 2 with (step I) 2-(thiophen-3-yl)acetic acid (0.568 g; 3.78 mmol), oxalyl chloride (0.352 mL; 4.16 mmol) in dichloromethane (12 mL) with few drops of DMF; (step II) ethyl 2-amino-2-(hydroxyimino)acetate (0.5 g; 3.78 mmol); N,N diisopropylethylamine (1.05 mL; 6.06 mmol) in dichloromethane (6 mL) and (step III) pyridine (18 mL). The crude material was purified by flash chromatography on silica (eluent 20 to 100% ethyl acetate in heptane) to yield 0.343 g (38%) of ethyl 5-(thiophen-3-ylmethyl)-1,2,4-oxadiazole-3-carboxylate as a yellow solid.

Workup

  1. customThis compound was prepared
  2. customThe crude material was purified by flash chromatography on silica (eluent 20 to 100% ethyl acetate in heptane)

Sources & evidence

ORD record
ord-5b7e18e865d74e309b3da04ad4b2be92
Source dataset
uspto-grants-2016_09
Patent number
US09434722B2

Linked notes

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