Réaction #47072

Équation de réaction

4-fluorobenzaldehyde

2-methyl-cis-4,5-diphenyl-4,5-dihydro-imidazole-1-carboxylic acid, tert-butyl ester

2-Methyl-cis-4,5-diphenyl-4,5-dihydro-imidazole-1-carboxylic acid, tert-butyl ester

n-butyl lithium

hexane

ammonium chloride

→

product 256

Rendement 45.8%

2-[2-(4-Fluorophenyl)-2-hydroxyethyl]-cis-4,5-diphenyl-4,5-dihydro-imidazole-1-carboxylic acid, tert-butyl ester

Rendement 45.8%

Solvants

THF

EtOAc

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGthe mixture is stirred for 1 h at −70° C. and 1 h at RT
2. 2
   Autrethe organic layer is separated
3. 3
   Lavagewashed with brine
4. 4
   Séchagedried (MgSO4)
5. 5
   Filtrationfiltered
6. 6
   Autrethe residue purified by chromatography on silica gel
7. 7
   Lavageelution with dichloromethane:EtOAc (9:1)

Mode opératoire

To a cold (−70° C.) solution of 2-methyl-cis-4,5-diphenyl-4,5-dihydro-imidazole-1-carboxylic acid, tert-butyl ester (253) (3.36 g, 10.0 mmol) in THF is added 1.6M n-butyl lithium in hexane (6.9 mL, 11.0 mmol), and the mixture is stirred for 1 h at −70° C. To the reaction mixture is added 4-fluorobenzaldehyde (1.18 mL, 11.0 mmol), and the mixture is stirred for 1 h at −70° C. and 1 h at RT. To the reaction mixture is added ammonium chloride solution, EtOAc, and the organic layer is separated, and washed with brine, dried (MgSO4), and filtered. The filtrate is rotary evaporated, and the residue purified by chromatography on silica gel; elution with dichloromethane:EtOAc (9:1) gives 2.11 g of the product 256. 1H NMR (CDCl3) δ 7.60-7.45 (m, 2 H), 7.15-6.90 (m, 10 H), 6.85-6.60 (m, 2 H), 5.70-5.20 (m, 4 H), 3.60-3.10 (m, 2 H), 1.18 (s, 9 H); MS: m/z 461 (M++1).

Source