Trifluoroacetic acid → Tert-butyl 5-[2-(1(rs)-aminopropyl)-4(rs),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(rs)-methylvalerate

HRID 842408

Reaction equation

HRID 842408 reaction equation
Cl[CH:2]([B:5]1[O:9][C:8]([CH2:11][CH2:12][CH:13]([CH3:22])[CH2:14][C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])([CH3:10])[C:7]([CH3:24])([CH3:23])[O:6]1)[CH2:3][CH3:4].C[Si]([N-:29][Si](C)(C)C)(C)C.[Li+].FC(F)(F)C(O)=O>O1CCCC1>[NH2:29][CH:2]([B:5]1[O:9][C:8]([CH2:11][CH2:12][CH:13]([CH3:22])[CH2:14][C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])([CH3:10])[C:7]([CH3:24])([CH3:23])[O:6]1)[CH2:3][CH3:4]

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 2733832Lithium HexamethyldisilazideHCID 22619127Tert-butyl 5-[2-(1(rs)-chloropropyl)-4(rs),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(rs)-methylvalerate

Product 1

HCID 22619085Tert-butyl 5-[2-(1(rs)-aminopropyl)-4(rs),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(rs)-methylvalerateYield 129.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

0.82 g (2.27 mmol) of tert-butyl 5-[2-(1(RS)-chloropropyl)-4(RS),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(RS)-methylvalerate was dissolved in 10 ml of tetrahydrofuran and then cooled to −78° C. under a nitrogen atmosphere. 2.3 ml (2.3 mmol) of 1M lithium bis(trimethylsilyl)amide in tetrahydrofuran were added dropwise. The solution was then stirred overnight while slowly warming to room temperature. The solvent was removed by evaporation and the residue was taken up in diethyl ether. Insoluble material was removed by filtration and the filtrate was cooled to 0° C. 0.52 ml (6.8 mmol) of trifluoroacetic acid was added and the solution was stirred at 0° C. for 30 minutes. The solution was evaporated and the residue was co-evaporated with toluene to give 1 g of tert-butyl 5-[2-(1(RS)-aminopropyl)-4(RS), 5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(RS)-methylvalerate as an oil which was used in the next step without purification.

Workup

  1. temperaturewhile slowly warming to room temperature
  2. customThe solvent was removed by evaporation
  3. customInsoluble material was removed by filtration
  4. temperaturethe filtrate was cooled to 0° C
  5. stirringthe solution was stirred at 0° C. for 30 minutes
  6. customThe solution was evaporated

Sources & evidence

ORD record
ord-62f3901f00514db0bb39c4c0d2a9862c
Source dataset
uspto-grants-2002_04
Patent number
US06372883B1

Linked notes

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