Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → Ethyl 4-(3-bromophenyl)butanoate

HRID 1206

反応式

HRID 1206 の反応式
[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][CH:9]=O)[CH:5]=[CH:6][CH:7]=1.[C:11]([CH:16]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([O:13][CH2:14][CH3:15])=[O:12]>>[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][CH2:9][CH2:16][C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:5]=[CH:6][CH:7]=1

参加物

3

反応物 2

HCID 70670Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl esterHCID 20387554(3-Bromophenyl)acetaldehyde

生成物 1

HCID 11492759Ethyl 4-(3-bromophenyl)butanoate

実験手順

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.

後処理

  1. customto provide

出典と根拠

ORDレコード
ord-81448799139447a985ca454877c95d87
出典データセット
uspto-grants-1998_03
特許番号
US05723620

関連ノート

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