Tetrahydrofuran → 3-[(5-ethoxycarbonyl-2-thienyl)-methylene]-2,4(3H,5H)-furandione

HRID 982404

Reaction equation

HRID 982404 reaction equation
[CH2:1]1[C:6](=[O:7])[O:5][CH2:4][C:2]1=[O:3].C([C:10]1[CH:14]=[C:13]([C:15]([OH:17])=[O:16])[S:12][C:11]=1[CH:18]=O)C.[CH2:20]1COC[CH2:21]1>>[CH2:20]([O:17][C:15]([C:13]1[S:12][C:11]([CH:18]=[C:1]2[C:2](=[O:3])[CH2:4][O:5][C:6]2=[O:7])=[CH:10][CH:14]=1)=[O:16])[CH3:21]

Participants

4

Reactant 3

HCID 8028TetrahydrofuranHCID 521261Tetronic acidHCID 200677334-Ethyl-5-formyl-thiophene-2-carboxylic acid

Product 1

HCID 538066413-[(5-ethoxycarbonyl-2-thienyl)-methylene]-2,4(3H,5H)-furandioneYield 63%

Procedure

0.494 gm of tetronic acid (FW=100, 4.94 mmole) and 2.00 gm of ethyl-5-carboxy-2-thiophenecarboxaldehyde (FW=184, 10.9 mole) in 2mL of THF and 10 mL of concentrated HC1 was reacted as before by applying heat and efficient stirring. The total reaction time was 10 minutes. Workup and recrystallization from methanol gave 0.827 gm (63%) of the product. M. p. 204°-205.5° C. C12H10O4S: %C 564.13; %H 3.79; found %C 53.93; %H 4.00. NMR results: 1HNMR (d6DMSO (H2)/TMS δ1.39 (3H, t, 7HZ); 4.39 (2H, q, 7Hz); 7.83 (1H, d, 4Hz); 8.21 (2H, m).

Workup

  1. temperatureby applying heat
  2. customWorkup and recrystallization from methanol

Sources & evidence

ORD record
ord-90d536ed0ea7481fb3e808f3653f70c9
Source dataset
uspto-grants-1991_02
Patent number
US04996227

Linked notes

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