Thiophenol → Ethyl 4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate

HRID 1842460Notes

Reaction equation

HRID 1842460 reaction equation
[N+](C1C=CC=CC=1S([N:13]1[CH2:18][CH2:17][N:16]2[N:19]=[C:20]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH:21]=[C:15]2[CH2:14]1)(=O)=O)([O-])=O.C(=O)([O-])[O-].[Cs+].[Cs+].C1(S)C=CC=CC=1>C(#N)C>[N:19]1[N:16]2[CH2:17][CH2:18][NH:13][CH2:14][C:15]2=[CH:21][C:20]=1[C:22]([O:24][CH2:25][CH3:26])=[O:23]

Participants

5

Reactant 3

HCID 7969ThiophenolHCID 10796Cesium carbonateHCID 58465606HCID 58465606, compound

Product 1

HCID 45934303Ethyl 4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylateYield 84%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a mixture of ethyl 5-[(2-nitrophenyl)sulfonyl]-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate (0.216 g, 0.568 mmol) and cesium carbonate (0.35 g, 1.1 mmol) was added a solution of benzenethiol (0.11 mL, 1.1 mmol) in acetonitrile (1 mL). The resulting reaction mixture was stirred at room temperature for 1 hour. The solvent was removed in vacuo and the residue applied directly to silica purification (5% MeOH/DCM with 1% Et3N) to afford Intermediate 17 as a white solid (0.093 g, 84%). LC-MS: (FA) ES+196; 1H NMR (400 MHz, CDCl3) δ 6.49 (s, 1H), 4.35 (q, J=7.1 Hz, 2H), 4.17-4.13 (m, 2H), 4.04 (s, 2H), 3.29-3.25 (m, 2H), 1.74 (s, 1H), 1.35 (t, J=7.1 Hz, 3H).

Workup

  1. customThe resulting reaction mixture
  2. customThe solvent was removed in vacuo
  3. customthe residue applied directly to silica purification (5% MeOH/DCM with 1% Et3N)

Sources & evidence

ORD record
ord-be3eb2f6ffac439b88f100976e047ece
Source dataset
uspto-grants-2015_02
Patent number
US08946223B2

Reaction notes

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