Benzaldehyde → 2,3-Dimethyl-5-(alpha-hydroxybenzyl)thiophene

HRID 1278790Notes

Reaction equation

HRID 1278790 reaction equation
C([Li])CCC.[CH3:6][C:7]1[S:8][CH:9]=[CH:10][C:11]=1[CH3:12].[CH:13](=[O:20])[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.[Cl-].[NH4+]>C1COCC1>[CH3:12][C:11]1[CH:10]=[C:9]([CH:13]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[OH:20])[S:8][C:7]=1[CH3:6]

Participants

6

Reactant 4

HCID 240BenzaldehydeHCID 25517Ammonium ChlorideHCID 342952,3-DimethylthiopheneHCID 178418339Butyllithium

Product 1

HCID 116371262,3-Dimethyl-5-(alpha-hydroxybenzyl)thiopheneYield 80%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

n-Butyl lithium (19.6 ml, 49.1 mmol, 2.5 N in hexanes) was added dropwise to a stirred solution of 2,3- dimethyl-thiophene (5.0 g, 44.6 mmol) in THF (100 mL) at −78° C. under a dry nitrogen atmosphere. The solution was warmed to 0° C. for 30 min and recooled to −78° C. whereupon benzaldehyde (5.0 mL, 49.1 mmol) was added. After an additional 45 minutes, sat. aq. ammonium chloride was added and the reaction mixture was partitioned between water and ether. The ether phase was washed with brine and concentrated. The resultant oil was triturated with pet. ether to provide the title compound as a white solid (7.77 g, 80%): mp 80-81° C.: NMR (CDCl3); δ 7.45 (ddd, J=8, 1, 1 Hz, 2H), 7.37 (ddd, J=8, 8, 1 Hz, 2H), 7.3 (m, 1H), 6.57 (s, 1H), 6.93 (s, 1H, OH), 2.29 (s, 3H), 2.05 (s, 3H); MS (El) (M+) 218 (45%, MI): Anal. Calc. for C13H14OS: C, 71.52, H, 6.46, N, 0.00. Found: C, 71.41, H, 6.42, N, 0.09.

Workup

  1. additionwas added
  2. customthe reaction mixture was partitioned between water and ether
  3. washThe ether phase was washed with brine
  4. concentrationconcentrated
  5. customThe resultant oil was triturated with pet. ether

Sources & evidence

ORD record
ord-4787f4aec21d41b9b215c58d85d9b0af
Source dataset
uspto-grants-2002_09
Patent number
US06444670B2

Reaction notes

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