Ethyl 3-(bromophenyl)acetate → (3-Bromophenyl)acetaldehyde

HRID 611005Notes

Reaction equation

HRID 611005 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][C:9](OCC)=[O:10])[CH:5]=[CH:6][CH:7]=1.[H-].C([Al+]CC(C)C)C(C)C>>[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][CH:9]=[O:10])[CH:5]=[CH:6][CH:7]=1

Participants

3

Reactant 2

HCID 11470552Ethyl 3-(bromophenyl)acetate2×HCID 21225700Diisobutylaluminumhydride

Product 1

HCID 20387554(3-Bromophenyl)acetaldehyde

Procedure

Compound G can be obtained as described in J. Med. Chem. 1995, 38, 4764-4767, and as shown in Reaction Scheme 1. Thus, referring now specifically to Reaction Scheme 1, ethyl 3-bromophenylacetate (Compound B, made by esterification of 3-bromophenylacetic acid) is reduced with diisobutylaluminum hydride (DIBAL H) to yield (3-bromophenyl)acetaldehyde. (3-Bromophenyl)acetaldehyde is reacted in a Wittig reaction with (carbethoxymethylene)triphenylphosphorane to provide a mixture of E and Z ethyl 4-(3-bromophenyl)but-2-enoates. The latter compounds are hydrogenated to yield ethyl 4-(3-bromophenyl)butanoate (Compound D). Compound D is reacted with the Grignard reagent derived from methylbromide to give the tertiary alcohol 5-(3-bromophenyl)-2-methylpentan-2-ol (Compound E) (It should be apparent to those skilled in the art, that the choice of the Grignard reagent used in this reaction step determines the nature of the R1 substituent in the resulting compounds of the invention.) Compound E is then treated with acid to cyclize it and to form

Workup

  1. custom1995, 38, 4764-4767, and as shown in Reaction Scheme 1

Sources & evidence

ORD record
ord-d30a943150004829956e972058dda030
Source dataset
uspto-grants-1999_12
Patent number
US05998655

Reaction notes

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