2-Methylterephthalic acid → 2-carboxy-5-oxo-5H-dibenzo[a,d]cycloheptene

HRID 329320ノート

反応式

HRID 329320 の反応式
[CH3:1][C:2]1[CH:10]=[C:9]([C:11]([OH:13])=[O:12])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=O>CO>[O:6]=[C:4]1[C:3]2[CH:7]=[CH:8][C:9]([C:11]([OH:13])=[O:12])=[CH:10][C:2]=2[CH:1]=[CH:1][C:2]2[CH:10]=[CH:9][CH:8]=[CH:7][C:3]1=2

参加物

3

反応物 1

HCID 2280862-Methylterephthalic acid

生成物 1

HCID 125630012-carboxy-5-oxo-5H-dibenzo[a,d]cycloheptene

試薬・触媒・溶媒 1

HCID 887Methanol溶媒

実験手順

The starting material (i.e., 5-oxo-5H-dibenzo[a,d]-cycloheptene-2-carboxylic acid) is prepared by esterifying 2-methylterephthalic acid with methanol, in the presence of acid catalyst, to afford the corresponding dimethyl ester which, in turn, is reacted with N-bromosuccinimide to afford 2-bromomethylterephthalic acid dimethyl ester. This diester is reacted with triphenylphosphine to afford 2,5-bis(carbomethoxy)-benzyltriphenylphosphonium bromide which is treated with benzaldehyde and diazabicyclononene to afford, after alkaline hydrolysis, cis and trans-stilbene 2,5-dicarboxylic acid. Hydrogenation of this latter compound with hydrogen over a 5% palladium on carbon catalyst affords 2-(2-phenethyl)terephthalic acid. Treatment with polyphosphoric acid yields 5-oxo-5H-dibenzo[a,d]-cycloheptane-2-carboxylic acid which can be recrystallized from aqueous dimethylformamide.

出典と根拠

ORDレコード
ord-f6059fe531d74d8ab9aba0e9b2a2d9f8
出典データセット
uspto-grants-1977_04
特許番号
US04020094

反応ノート

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