7-Bromo-4,4-dimethyl-1,2,3,4-tetrahydronaphthalen-1-one → (3-Bromophenyl)acetaldehyde

HRID 1205

Reaktionsgleichung

Reaktionsgleichung von HRID 1205
[H][H].BrC1C=C2C(C(C)(C)CCC2=O)=CC=1.[Br:17][C:18]1[CH:19]=[C:20]([CH2:24][C:25](OCC)=[O:26])[CH:21]=[CH:22][CH:23]=1.[H-].C([Al+]CC(C)C)C(C)C>>[Br:17][C:18]1[CH:19]=[C:20]([CH2:24][CH:25]=[O:26])[CH:21]=[CH:22][CH:23]=1

Komponenten

5

Edukt 4

HCID 107533577-Bromo-4,4-dimethyl-1,2,3,4-tetrahydronaphthalen-1-one2×HCID 11470552Ethyl 3-(bromophenyl)acetate2×HCID 21225700DiisobutylaluminumhydrideHCID 178418361HCID 178418361, Verbindung

Produkt 1

HCID 20387554(3-Bromophenyl)acetaldehyde

Versuchsvorschrift

In the preferred compounds of the invention the two R1 substituents are methyl, and the R2 and R3 substituents are hydrogen. Reaction Scheme 4 illustrates a synthetic process for preparing 7-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1-one (Compound G) which serves as a starting material for the synthesis of several preferred compounds of the invention. Thus, referring now specifically to Reaction Scheme 4, ethyl 3-bromophenylacetate (Compound B, made by esterification of 3-bromophenylacetic acid) is reduced with diisobutyl aluminum 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 6-bromo-1,2,3,4-tetrahydro-1,1-dimethylnaphthalene (Compound F). Compound F is in the scope of Formula 17, and in accordance with Reaction Schemes 2 and 3 serves as the starting material in the synthesis of several preferred compounds of the invention. Compound F is oxidized with chromium trioxide to yield 7-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1(2H)-one (Compound G). Compound G is covered by Formula 10 and in accordance with Reaction Scheme 1 serves as a starting material in the synthesis of several preferred compounds of the invention.

Aufarbeitung

  1. customReaction Scheme 4
  2. customserves as a starting material for the synthesis of several preferred compounds of the invention

Quellen und Nachweise

ORD-Eintrag
ord-50401cea459a444786f5e8507d29997b
Quelldatensatz
uspto-grants-1998_03
Patentnummer
US05723620

Verknüpfte Notizen

Wird geladen…