Reaktion #583813

Reaktionsgleichung

benzyl bromide

benzyl zinc

compound 27

methyl 2-bromo-4-nitro-benzoate

benzyl zinc

→

compound 28

methyl 2-benzyl-4-nitro-benzoic acid

Lösungsmittel

THF

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITThe mixture was left
2. 2
   SonstigeThe resulting black reaction mixture was quenched with 2N HCl (250 mL)
3. 3
   Extraktionextracted with Ethyl acetate (2×100 mL)
4. 4
   WaschenThe combined organics were washed with water (50 mL) and brine (50 mL)
5. 5
   Filtrationfiltered through phase
6. 6
   Sonstigeseparating paper
7. 7
   Sonstigeevaporated to an orange gum
8. 8
   SonstigeThis was purified by chromatography on silica (Merck, 9385)
9. 9
   Wascheneluting with 10% ethyl acetate/i-hexane

Vorschrift

A solution of benzyl bromide (2.0 mL, 17.3 mmol) in THF (10 mL) was added dropwise at 0° C. to a stirred suspension of zinc dust (1.7 g, 26 mmol) in THF (10 mL) which had been activated according to the method described by Knochel (J.O.C. 53, 2392, 1988). The mixture was left to warm to ambient temperature and stir for 3 h. An aliquot (6.5 mmol) of the supernatent containing the benzyl zinc reagent was then added to a stirred solution of compound 27 (3.85 mmol) and Pd(dba)3 (0.0385 mmol) in THF (10 mL) at ambient temperature under argon. After 1 hr a second aliquot (6.5 mmol) of the benzyl zinc reagent was added. The resulting black reaction mixture was quenched with 2N HCl (250 mL) and extracted with Ethyl acetate (2×100 mL). The combined organics were washed with water (50 mL) and brine (50 mL), filtered through phase separating paper and evaporated to an orange gum. This was purified by chromatography on silica (Merck, 9385) eluting with 10% ethyl acetate/i-hexane to give methyl 2-benzyl-4-nitro-benzoic acid (compound 28).

Quelle