Pentane → 4-(4-Isopropoxymethylbenzyl)phenyl carbamic acid 2-trimethylsilanylethyl ester

HRID 634793Notes

Reaction equation

HRID 634793 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([CH2:8][O:9][CH:10]([CH3:12])[CH3:11])=[CH:4][CH:3]=1.C([Li])(C)(C)C.CCCCC.C([Sn](Cl)(CCCC)CCCC)CCC.[CH3:37][Si:38]([CH3:54])([CH3:53])[CH2:39][CH2:40][O:41][C:42](=[O:52])[NH:43][C:44]1[CH:49]=[CH:48][C:47]([CH2:50]Cl)=[CH:46][CH:45]=1>O1CCCC1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.CN(C)P(N(C)C)(N(C)C)=O>[CH3:53][Si:38]([CH3:37])([CH3:54])[CH2:39][CH2:40][O:41][C:42](=[O:52])[NH:43][C:44]1[CH:45]=[CH:46][C:47]([CH2:50][C:2]2[CH:7]=[CH:6][C:5]([CH2:8][O:9][CH:10]([CH3:12])[CH3:11])=[CH:4][CH:3]=2)=[CH:48][CH:49]=1

Participants

9

Reactant 5

HCID 8003PentaneHCID 15096Tributyltin ChlorideHCID 218769451-Bromo-4-((propan-2-yloxy)methyl)benzeneHCID 53690460(4-Chloromethylphenyl) carbamic acid 2-trimethylsilanyl-ethyl esterHCID 178418306HCID 178418306, compound

Product 1

HCID 691459544-(4-Isopropoxymethylbenzyl)phenyl carbamic acid 2-trimethylsilanylethyl esterYield 26%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 8028TetrahydrofuranSolventHCID 12679HexamethylphosphoramideSolvent

Conditions

Temperature
65 °C

Procedure

To a stirred solution of 1-bromo-4-isopropoxymethyl-benzene (300 mg, 13.1 mmol) (prepared as described in Preparation 1) in dry tetrahydrofuran (1.4 mL) at −78° C. under argon atmosphere was added dropwise 1.7M tert-butyllithium in pentane (1.62 mL, 2.75 mmol). After the mixture was stirred for about 20 minutes, tri-n-butyltin chloride (0.35 mL, 1.31 mmol) was added. The mixture was allowed to reach 0° to 5° C. and stirred for about 1 hour. A mixture of (4-chloromethylphenyl) carbamic acid 2-trimethylsilanyl-ethyl ester (374 mg, 13.1 mmol) (prepared as described in Preparation 2), hexamethylphosphoramide (4.4 mL), tetrakis(triphenylphosphine)palladium(0) (29.3 mg, 0.025 mmol) was added at 0° to 5° C., and then heated to about 65° C. for 20 hours. The solution was partitioned between water (15 mL) and diethyl ether (15 mL). The aqueous phase was extracted with diethyl ether, and the combined organic layers were washed with water and brine, dried (Na2SO4), and evaporated in vacuo. The residue was dissolved in acetonitrile, washed with hexane (2×20 mL), dried (Na2SO4), concentrated in vacuo, and purified by flash chromatography to give pure 4-(4-isopropoxymethylbenzyl)phenyl carbamic acid 2-trimethylsilanyl-ethyl ester (204 mg, 26%) as clear oil.

Workup

  1. customto reach 0° to 5° C.
  2. stirringstirred for about 1 hour
  3. additionwas added at 0° to 5° C.
  4. customThe solution was partitioned between water (15 mL) and diethyl ether (15 mL)
  5. extractionThe aqueous phase was extracted with diethyl ether
  6. washthe combined organic layers were washed with water and brine
  7. dry with materialdried (Na2SO4)
  8. customevaporated in vacuo
  9. dissolutionThe residue was dissolved in acetonitrile
  10. washwashed with hexane (2×20 mL)
  11. dry with materialdried (Na2SO4)
  12. concentrationconcentrated in vacuo
  13. custompurified by flash chromatography

Sources & evidence

ORD record
ord-ab462fc7c90048b38c491d539c3d8822
Source dataset
uspto-grants-2001_02
Patent number
US06184242B2

Reaction notes

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