Water → HCID 15680102, compound

HRID 2379892Notes

Reaction equation

HRID 2379892 reaction equation
[SH:1][C:2]1[NH:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[N:3]=1.Br[CH2:12][CH2:13][CH2:14][CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17].C(=O)([O-])[O-].[K+].[K+].O>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.O1CCCC1>[C:16]([CH2:15][CH2:14][CH2:13][CH2:12][S:1][C:2]1[NH:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[N:3]=1)([O:18][CH2:19][CH3:20])=[O:17]

Participants

7

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 84580Ethyl 5-bromovalerateHCID 178527775HCID 178527775, compound

Product 1

HCID 15680102HCID 15680102, compound

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 8028TetrahydrofuranSolvent

Procedure

Part A. A solution of 2-mercapto-1H-benzimidazole (4.75 g, 31.6 mmol), ethyl 5-bromovalerate (5.00 mL, 31.6 mmol), potassium carbonate (5.68 g, 41.1 mmol), and tetra-n-butylammonium iodide (2.33 g, 6.31 mmol) in tetrahydrofuran (200 mL) was heated to reflux for 24 hours. The solution was cooled, and poured into water (200 mL). The layers were separated, and the aqueous layer was extracted with methylene chloride (2×200 mL). All three organic phases were washed over brine, combined, dried over anhydrous magnesium sulfate, filtered and evaporated to afford a pale yellow oil. The oil was purified by elution through a short plug of silica gel (1:1 ethyl acetate-hexane) to afford the product, 2-[4-(carboethoxy)butylthio]-1H-benzimidazole, as a waxy solid, m.p. 88°-90° C. (8.03 g, 28.9 mmol, 91%). 1H NMR (CDCl3): 10.61 (1H, br s); 7.66 (1H, br s); 7.36 (1H, br s); 7.19 (2H, dd, J=5.7, 2.7 Hz); 4.12 (2H, q, J=7.0 Hz); 3.30 (2H, t, J=6.2 Hz); 2.32 (2H, t, J=5.9 Hz); 1.95-1.74 (4H, m); 1.24 (3H, t, J=7.0 Hz).

Workup

  1. temperatureto reflux for 24 hours
  2. temperatureThe solution was cooled
  3. customThe layers were separated
  4. extractionthe aqueous layer was extracted with methylene chloride (2×200 mL)
  5. washAll three organic phases were washed over brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. filtrationfiltered
  8. customevaporated
  9. customto afford a pale yellow oil
  10. customThe oil was purified by elution through a short plug of silica gel (1:1 ethyl acetate-hexane)

Sources & evidence

ORD record
ord-ae1344a184d64af8be74e9148b2e248f
Source dataset
uspto-grants-1994_11
Patent number
US05364875

Reaction notes

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