Ethyl Acetate → Hydrogen Bromide

HRID 1603954Notes

Reaction equation

HRID 1603954 reaction equation
C[O:2][C:3]1[CH:8]=[CH:7][C:6]([O:9]C)=[CH:5][C:4]=1[O:11]C.[Br:13]Br.[C:15]([O:18]CC)(=[O:17])[CH3:16]>C(Cl)(Cl)Cl.C(Cl)(Cl)(Cl)Cl>[BrH:13].[CH:7]1[C:6](=[O:9])[CH:5]=[C:4]([OH:11])[C:3]([OH:2])=[CH:8][C:16]=1[C:15]([OH:18])=[O:17]

Participants

7

Reactant 3

HCID 8857Ethyl AcetateHCID 24408BromineHCID 672841,2,4-Trimethoxybenzene

Product 2

HCID 260Hydrogen BromideHCID 205013,6-Dihydroxy-5-oxo-1,3,6-cycloheptatriene-1-carboxylic acid

Reagents, catalysts & solvents 2

HCID 5943Carbon TetrachlorideSolventHCID 6212ChloroformSolvent

Procedure

Puberulic acid is also obtainable by direct chemical synthesis, as disclosed by Johns et al., Jour. Chem. Soc. 1954, 198. According to this method, a solution of 3,4,6-trimethoxycycloheptatriene-caboxylic acid (an intermediate obtained by reacting diazoacetic ester and 1,2,4-trimethoxybenzene) in chloroform is reacted with a solution of bromine in carbon tetrachloride; the obtained precipitate is then heated in ethyl acetate, cooled in ice and then hydrolyzed with hydrobromic acid, obtaining stipitatic acid. Said stipitatic acid is then reacted with bromine, in order to obtain monobromostipitatic acid which is in turn reacted with potassium hydroxide to obtain the desired puberulic acid.

Workup

  1. temperaturecooled in ice

Sources & evidence

ORD record
ord-2834295b1515457aa229f827df589c87
Source dataset
uspto-grants-1999_11
Patent number
US05990160

Reaction notes

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