2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → p-Propylphenyl 4-pentyloxy-2,3-difluorobiphenyl-4'-carboxylate

HRID 1198329Notes

Reaction equation

[CH2:1]([C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][CH:5]=1)[CH2:2][CH3:3].[F:11][C:12]1[C:17]([F:18])=[C:16](OCCCCC)[CH:15]=[CH:14][C:13]=1C1C=CC(C(O)=O)=CC=1.[CH2:34](OC1C=CC=C(F)C=1F)[CH2:35][CH2:36][CH2:37][CH3:38].C([Li])CCC.CN(CCN(C)C)C.CCO[C:64]([CH:66]1[CH2:72][CH2:71][C:69](=O)[CH2:68][CH2:67]1)=[O:65].ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl.[OH-:87].[K+].C1CCC(N=C=NC2CCCCC2)CC1>C1COCC1.C1(C)C=CC=CC=1.C(Cl)Cl>[CH2:34]([O:87][C:13]1[CH:14]=[CH:15][C:16]([C:69]2[CH:68]=[CH:67][C:66]([C:64]([O:10][C:7]3[CH:8]=[CH:9][C:4]([CH2:1][CH2:2][CH3:3])=[CH:5][CH:6]=3)=[O:65])=[CH:72][CH:71]=2)=[C:17]([F:18])[C:12]=1[F:11])[CH2:35][CH2:36][CH2:37][CH3:38]

Participants

Conditions

Temperature: -70 °C

Procedure

13.6 g of p-propylphenol and 32 g of 2,3-difluoro-4-pentyloxybiphenyl-4'-carboxylic acid (preparation of 4-pentyloxy-2,3-difluorobiphenyl-4'-carboxylic acid: pentyloxy-2,3-difluorobenzene is metalated with an equimolar amount of butyllithium and TMEDA under the customary conditions at -70° C. in THF, and the reaction mixture is then stirred at -70° C. for 4 hours and reacted with an equimolar amount of chlorotriisopropyl orthotitanate at the same temperature. The reaction mixture is allowed to warm slowly to -30+ C., an equimolar amount of ethyl cyclohexanone-4-carboxylate is then added and the mixture is stirred for 12 hours while warming slowly to room temperature. The reaction mixture is hydrolysed with ice-cold dilute hydrochloric acid, stirred briefly and filtered over celite. The filtrate is extracted with MTB ether and the organic phase is dried and evaporated. The residue is taken up in ethanol, a little hydrochloric acid is added and the mixture is boiled under reflux for 12 hours. After addition of water, the product is isolated in the customary manner and heated at the boiling point together with twice the molar amount of DDQ in toluene. The mixture is then worked up in the customary manner and the ester is hydrolysed with a small excess of ethanolic KOH at room temperature. The acid is purified by crystallization.) are initially introduced into 250 ml of methylene chloride together with a catalytic amount of DMAP, and a solution of 0.1 mol of DCC in methylene chloride is added dropwise at 0° C. The reaction mixture is stirred at room temperature for 12 hours, the dicyclohexylurea which has precipitated is then filtered off with suction and the organic phase is worked up in the customary manner. p-Propylphenyl 4-pentyloxy-2,3-difluorobiphenyl-4'-carboxylate is obtained.

Workup

customreacted with an equimolar amount of chlorotriisopropyl orthotitanate at the same temperature
temperatureto warm slowly to -30+ C
stirringthe mixture is stirred for 12 hours
temperaturewhile warming slowly to room temperature
stirringstirred briefly
filtrationfiltered over celite
extractionThe filtrate is extracted with MTB ether
customthe organic phase is dried
customevaporated
additiona little hydrochloric acid is added
temperatureunder reflux for 12 hours
additionAfter addition of water
customthe product is isolated in the customary manner
customat room temperature
customThe acid is purified by crystallization
addition) are initially introduced into 250 ml of methylene chloride together with a catalytic amount of DMAP
stirringThe reaction mixture is stirred at room temperature for 12 hours
customthe dicyclohexylurea which has precipitated
filtrationis then filtered off with suction

Sources & evidence

ORD record: ord-b84bd67a5314456fabf1f7c059ee2d14
Source dataset: uspto-grants-1994_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05279764

Reaction notes

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