Phenyl cyanate → 4-(p-Chlorophenyl)-4-methyl-2-pentynenitrile

HRID 610847Notes

Reaction equation

Br[C:2](Br)=[CH:3][C:4]([C:7]1[CH:12]=[CH:11][C:10]([Cl:13])=[CH:9][CH:8]=1)([CH3:6])[CH3:5].C([Li])CCC.C1(O[C:27]#[N:28])C=CC=CC=1>O1CCCC1.CCCCCC.C(OCC)(=O)C.[OH-].[Na+]>[Cl:13][C:10]1[CH:11]=[CH:12][C:7]([C:4]([CH3:6])([CH3:5])[C:3]#[C:2][C:27]#[N:28])=[CH:8][CH:9]=1

Participants

Conditions

Temperature: 10 °C

Procedure

A solution of 1,1-dibromo-3-(p-chlorophenyl)-3-methyl-1-butene (38.5 g, 0.113 mol) in tetrahydrofuran is treated with n-butyllithium (0.25 mol, 100 mL of a 2.5M solution in hexane) under nitrogen over 45 minutes while maintaining the temperature below -65° C., stirred overnight at dry ice/acetone bath temperature, treated dropwise with a solution of phenyl cyanate (14.89 g, 0.125 mol) in tetrahydrofuran over 30 minutes at -65° C. to -70° C., allowed to warm to 10° C., and diluted with ethyl acetate and 5% sodium hydroxide solution. The resultant mixture is extracted with ethyl acetate. The organic extracts are combined, washed sequentially with 5% sodium hydroxide solution and water, dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a residue. The residue is distilled to give the title product as an oil (18.7 g, bp 110-113° C./0.9 mm Hg, 80.7% yield).

Workup

temperaturewhile maintaining the temperature below -65° C.
extractionThe resultant mixture is extracted with ethyl acetate
washwashed sequentially with 5% sodium hydroxide solution and water
dry with materialdried over anhydrous sodium sulfate
concentrationconcentrated in vacuo
customto obtain a residue
distillationThe residue is distilled

Sources & evidence

ORD record: ord-281398f4406b468ca41f1d53a4c3713b
Source dataset: uspto-grants-1999_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05998673

Reaction notes

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