Ethyl isothiocyanate → 2,3-Diazaspiro[4.4]non-3-ene-2-carbothioic acid ethylamide

HRID 1484428Notes

Reaction equation

HRID 1484428 reaction equation
[CH2:1]1[C:5]2([CH2:9][CH2:8][CH2:7][CH2:6]2)[CH2:4][N:3]=[N:2]1.[CH2:10]([N:12]=[C:13]=[S:14])[CH3:11]>C(O)C>[CH2:10]([NH:12][C:13]([N:2]1[N:3]=[CH:4][C:5]2([CH2:9][CH2:8][CH2:7][CH2:6]2)[CH2:1]1)=[S:14])[CH3:11]

Participants

4

Reactant 2

HCID 10966Ethyl isothiocyanateHCID 547519672,3-Diaza-spiro[4.4]non-2-ene

Product 1

HCID 533541352,3-Diazaspiro[4.4]non-3-ene-2-carbothioic acid ethylamideYield 32%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

1.05 g (1 mol equiv.) 2,3-diaza-spiro[4.4]non-2-ene (synthesized as described in WO 2008/034863) and 0.95 mL (1.3 mol equiv.) ethyl isothiocyanate were added to 10 mL ethanol. The reaction mixture was refluxed for 2.5 hours under magnetic stirring. Silica gel was added and volatiles were removed in vacuo. The product was purified by flash chromatography on silica gel (Et2O:PA=1:2) and, after evaporation of the volatiles, stirred with diisopropylether and collected by filtration to yield 0.57 g (32%) of 2,3-diazaspiro[4.4]non-3-ene-2-carbothioic acid ethylamide. 1H NMR (400 MHz, CDCl3) δ 1.24 (t, J=7.2 Hz, 3H), 1.64-1.86 (m, 8H), 3.68 (dq, J=7.2, 5.5 Hz, 2H), 4.00 (s, 2H), 6.80 (s, 1H), 7.08-7.18 (br.s., 1H).

Workup

  1. temperatureThe reaction mixture was refluxed for 2.5 hours under magnetic stirring
  2. additionSilica gel was added
  3. customvolatiles were removed in vacuo
  4. customThe product was purified by flash chromatography on silica gel (Et2O:PA=1:2)
  5. customafter evaporation of the volatiles
  6. filtrationcollected by filtration

Sources & evidence

ORD record
ord-e38f8b01fb8c4cfd89fb7c4b83ac6443
Source dataset
uspto-grants-2016_08
Patent number
US09422244B2

Reaction notes

Loading…