2-tert-Butyl-1,3-diisopropylisourea → tert-butyl 6-cyclohexyl-4H-thieno[3,2-b]pyrrole-2-carboxylate

HRID 1008961Notes

Reaction equation

HRID 1008961 reaction equation
[CH:1]1([C:7]2[C:8]3[S:14][C:13]([C:15]([OH:17])=[O:16])=[CH:12][C:9]=3[NH:10][CH:11]=2)[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.C(NC(=NC(C)C)O[C:24]([CH3:27])([CH3:26])[CH3:25])(C)C.NC(=N)O>C(Cl)Cl>[CH:1]1([C:7]2[C:8]3[S:14][C:13]([C:15]([O:17][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:16])=[CH:12][C:9]=3[NH:10][CH:11]=2)[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]1

Participants

5

Reactant 3

HCID 110417822-tert-Butyl-1,3-diisopropylisoureaHCID 586790966-cyclohexyl-4H-thieno[3,2-b]pyrrole-2-carboxylic acidHCID 178513210HCID 178513210, compound

Product 1

HCID 67298608tert-butyl 6-cyclohexyl-4H-thieno[3,2-b]pyrrole-2-carboxylateYield 57%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A suspension of 6-cyclohexyl-4H-thieno[3,2-b]pyrrole-2-carboxylic acid (1 eq., prepared as described in WO2005/023819) in dry CH2Cl2 (0.19 M) was treated with tert-butyl N,N′-diisopropylimidocarbamate (2 eq.). The resulting clear solution was heated to reflux for 20 h. Addition of a further equivalent of isourea was required after 16 h to drive the reaction to complete conversion. After cooling down the solvent was evaporated in vacuo giving a residue that was purified by flash chromatography (PE:EtOAc, 10:1) affording the title compound (57%). 1H-NMR (400 MHz, DMSO-d6, 300 K, δ) 11.12 (bs, 1H), 7.55 (s, 1H), 7.08 (s, 1H), 2.60-2.50 (m, 1H), 1.99-1.67 (m, 5H), 1.51 (s, 9H), 1.45-1.19 (m, 5H). MS (ES+) m/z: 306 [M+H]+.

Workup

  1. temperatureThe resulting clear solution was heated
  2. temperatureto reflux for 20 h
  3. customthe reaction
  4. temperatureAfter cooling down the solvent
  5. customwas evaporated in vacuo
  6. customgiving a residue that
  7. customwas purified by flash chromatography (PE:EtOAc, 10:1)

Sources & evidence

ORD record
ord-47edfd3e30ed4b138257e59b4ce6eb82
Source dataset
uspto-grants-2011_07
Patent number
US07973026B2

Reaction notes

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