Sodium borohydride → 2-(6-Bromo-benzothiazol-2-yl)-ethanol

HRID 10402Notes

Reaction equation

HRID 10402 reaction equation
[BH4-].[Na+].C([O:5][C:6](=O)[CH2:7][C:8]1[S:9][C:10]2[CH:16]=[C:15]([Br:17])[CH:14]=[CH:13][C:11]=2[N:12]=1)C>C(O)C.C1COCC1>[Br:17][C:15]1[CH:14]=[CH:13][C:11]2[N:12]=[C:8]([CH2:7][CH2:6][OH:5])[S:9][C:10]=2[CH:16]=1

Participants

5

Reactant 2

HCID 4311764Sodium borohydrideHCID 21041509Ethyl 6-bromo-2-benzothiazoleacetate

Product 1

HCID 219800762-(6-Bromo-benzothiazol-2-yl)-ethanol

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a stirred mixture of sodium borohydride (1.11 g, 29.3 mmol) in ethanol (10 mL) at room temperature was added a solution of the (6-bromo-benzothiazol-2-yl)-acetic acid ethyl ester (2.2 g, 7.3 mmol) in THF (25 mL) at 23–28° C. The mixture was stirred at room temperature for 15 hr, cooled to 3° C. and quenched with 20 mL water at 3–5° C. The product was extracted with 40 mL methylene chloride, washed with 20 mL 15% NaCl and concentrated to crude oil. The crude product was purified by column chromatography (silica gel, 10:90 MeOH:CHCl3) to give the pure 2-(6-Bromo-benzothiazol-2-yl)-ethanol: 1H NMR (CDCl3 400 MHz) δ 3.30 (t, 2H, J=6 Hz), 4.11 (t, 2H, J=6 Hz), 7.54 (dd, 1H, J=5, 2 Hz), 7.78 (d, 1H, J=5 Hz), 7.95 (d, 1H, J=2 Hz). 13C NMR (CDCl3, 400 MHz) δ 36.7, 60.8, 118.3, 123.3, 129.2, 136.1, 151.3, 169.5; (DCI/NH3) m/z 258, 260 (M+H)+.

Workup

  1. temperaturecooled to 3° C.
  2. customquenched with 20 mL water at 3–5° C
  3. extractionThe product was extracted with 40 mL methylene chloride
  4. washwashed with 20 mL 15% NaCl
  5. concentrationconcentrated to crude oil
  6. customThe crude product was purified by column chromatography (silica gel, 10:90 MeOH:CHCl3)

Sources & evidence

ORD record
ord-d81361375ed643d0b99a999c148fc8ac
Source dataset
uspto-grants-2006_08
Patent number
US07094790B2

Reaction notes

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