p-Toluenesulfonic acid → 6-Bromo-4-tert-butyl-1,1-dimethyl-1,2-dihydronaphthalene

HRID 1361

Reaction equation

HRID 1361 reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([CH3:14])([CH3:13])[CH2:7][CH2:8][C:9]2=O)=[CH:4][CH:3]=1.[C:15]([Mg]Cl)([CH3:18])([CH3:17])[CH3:16].C1(C)C=CC(S(O)(=O)=O)=CC=1>O1CCCC1>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([CH3:14])([CH3:13])[CH2:7][CH:8]=[C:9]2[C:15]([CH3:18])([CH3:17])[CH3:16])=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 107533577-Bromo-4,4-dimethyl-1,2,3,4-tetrahydronaphthalen-1-one2×HCID 178418310HCID 178418310, compound

Product 1

HCID 158960196-Bromo-4-tert-butyl-1,1-dimethyl-1,2-dihydronaphthalene

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Reaction Scheme 9 discloses the preferred method of synthesis of a starting material from which certain examples for compounds of the invention within the scope of Formula 6 are preferably made. In accordance with this scheme 7-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1(2H)-one (Compound G) is reacted with t-butylmagnesium chloride in tetrahydrofuran in the presence of 1,3-dimethyl-3,4,5,6-tetrahydro-2(H)-pyrimidinone (DMPU). Thereafter, the resulting intermediate tertiary alcohol is heated in the presence of acid (p-toluenesulfonic acid) to give 7-bromo-1-(1,1-dimethylethyl)-3,4-dihydro-4,4-dimethylnaphthalene (Compound C42). Compound C42 is reacted with 1-ethoxyvinyltributyltin (EVTB) in the presence of Pd(0) catalyst to yield after acidic work-up 7-acetyl-1-(1,1-dimethylethyl)-3,4-dihydro-4,4-dimethylnaphthalene (Compound C43). Compound C43 is subjected to a sequence of reactions of the type described above in connection with Reaction Scheme 8, starting with a Horner Emmons reaction with diethyl cyanomethylphosphonate, to eventually provide ethyl 7-[4,4-dimethyl-3,4-dihydro-1-(1,1-dimethylethyl)-naphth-7-yl]-3,7-dimethyl-hepta-2(E),4(E),6(E)-trienoate (Compound C46). Compound C46 of the invention is within the scope of Formula 6. ##STR24##

Workup

  1. customReaction Scheme 9

Sources & evidence

ORD record
ord-36cb55ed95f3473c9784f61cd4f7575f
Source dataset
uspto-grants-1998_03
Patent number
US05723666

Linked notes

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