Diethyl (ethoxymethylene)malonate → Diethyl 2-((thiophen-3-ylamino)methylene)malonate

HRID 2370238Notes

Reaction equation

HRID 2370238 reaction equation
[NH2:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1C(OC)=O.CN1CCNCC1.CN1C(=O)CCC1.C(O[CH:28]=[C:29]([C:35]([O:37][CH2:38][CH3:39])=[O:36])[C:30]([O:32][CH2:33][CH3:34])=[O:31])C>CC#N>[S:4]1[CH:5]=[CH:6][C:2]([NH:1][CH:28]=[C:29]([C:30]([O:32][CH2:33][CH3:34])=[O:31])[C:35]([O:37][CH2:38][CH3:39])=[O:36])=[CH:3]1

Participants

6

Procedure

A mixture of methyl 3-aminothiophene-2-carboxylate 1 (5.0 g, 32 mmol, 1.0 eq), N-methyl piperazine (6.5 g, 64 mmol, 2.0 eq) and NMP (30 mL) was heated to reflux for 16 hours. After the decarboxylation was complete, the reaction mixture was allowed to cool to room temperature and diethyl 2-(ethoxymethylene)-malonate (7.0 g, 32 mmol, 2.0 eq) was added. The reaction mixture was heated to reflux for 4 h. The product was purified using SiO2 column chromatography (Hex/EtOAc; 100:0 to 80:20%) to obtain a light yellow powder, 5.0 g (31%). LC/MS (10-99% CH3CN/0.05% TFA gradient over 5 min): m/z 270.2, retention time 1.52 minutes. 1H NMR (DMSO-d6) δ: 10.80 (d, 1.0H, J=13.87 Hz, NH), 8.30 (d, 1.0H, J=13.94 Hz), 7.60 (dd, 1.0H, J=3.0 Hz, J′=2.0 Hz), 7.40 (dd, 1.0H, J=1.5 Hz, J′=3.13 Hz), 7.28 (dd, 1.0H, J=1.5 Hz, J′=5.2 Hz), 4.20 (q, 2H, J=7.0 Hz), 4.10 (q, 2H, J=7.0 Hz), 1.30 (m, 6H).

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 16 hours
  3. temperatureThe reaction mixture was heated
  4. temperatureto reflux for 4 h
  5. customThe product was purified
  6. customto obtain a light yellow powder, 5.0 g (31%)

Sources & evidence

ORD record
ord-150af244878442dea7ee86bef1d0f781
Source dataset
uspto-grants-2014_04
Patent number
US08710075B2

Reaction notes

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