2,5-Dimethoxytetrahydrofuran → ethyl 1'H-[1,3'-bipyrrole]-2'-carboxylate

HRID 523877Notes

Reaction equation

HRID 523877 reaction equation
CO[CH:3]1[CH2:7][CH2:6][CH:5](OC)O1.CC1C=CC(S([O-])(=O)=O)=CC=1.C1C=C[NH+]=CC=1.[CH2:27]([O:29][C:30]([C:32]1[NH:33][CH:34]=[CH:35][C:36]=1[NH2:37])=[O:31])[CH3:28]>O1CCOCC1>[N:37]1([C:36]2[CH:35]=[CH:34][NH:33][C:32]=2[C:30]([O:29][CH2:27][CH3:28])=[O:31])[CH:3]=[CH:7][CH:6]=[CH:5]1

Participants

5

Reactant 3

HCID 790982,5-DimethoxytetrahydrofuranHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 2773439Ethyl 3-amino-1H-pyrrole-2-carboxylate

Product 1

HCID 53253731ethyl 1'H-[1,3'-bipyrrole]-2'-carboxylateYield 53.1%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent2×

Procedure

To a stirred solution of 2,5-dimethoxytetrahydrofuran (b) (1.6 mL, 12.4 mmol, 1.3 equiv) and PPTS (3.2 g, 12.4 mmol, 1.3 equiv) in 1,4-dioxane (20 mL) at 50° C., a solution of aminopyrrole (a) (1.47 g, 9.55 mmol, 1.0 eq.) in 1,4-dioxane (6 mL) was added slowly. The resulting mixture was brought to reflux and stirred for 1 h. The reaction mixture was then concentrated, dissolved in EtOAc (50 mL) and dried over anhydrous MgSO4. The crude product was purified by flash column chromatography (10% EtOAc in Hexane) to give (c) as a yellow solid (1.036 g, 53% yield). 1H NMR (400 MHz, CDCl3) δ 8.99 (s, 1H), 7.04-7.01 (m, 2H), 6.89 (t, J=3.1 Hz, 1H), 6.29 (t, J=2.9 Hz, 1H), 6.27-6.24 (m, 2H), 4.28 (q, J=7.1 Hz, 2H), 1.29 (t, J=7.1 Hz, 3H).

Workup

  1. temperatureto reflux
  2. concentrationThe reaction mixture was then concentrated
  3. dissolutiondissolved in EtOAc (50 mL)
  4. dry with materialdried over anhydrous MgSO4
  5. customThe crude product was purified by flash column chromatography (10% EtOAc in Hexane)

Sources & evidence

ORD record
ord-a7745f5c7fa947c08ae36211df465746
Source dataset
uspto-grants-2016_05
Patent number
US09340501B2

Reaction notes

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