Carbon tetrabromide → Tert-butyl 4-(dibromomethylene)piperidine-1-carboxylate

HRID 1666430Notes

Reaction equation

HRID 1666430 reaction equation
C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[C:20]([Br:24])(Br)(Br)[Br:21].O=[C:26]1[CH2:31][CH2:30][N:29]([C:32]([O:34][C:35]([CH3:38])([CH3:37])[CH3:36])=[O:33])[CH2:28][CH2:27]1>ClCCl>[Br:21][C:20]([Br:24])=[C:26]1[CH2:31][CH2:30][N:29]([C:32]([O:34][C:35]([CH3:38])([CH3:37])[CH3:36])=[O:33])[CH2:28][CH2:27]1

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylate

Product 1

HCID 53486134Tert-butyl 4-(dibromomethylene)piperidine-1-carboxylateYield 120.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of triphenylphosphine (155.6 g, 0.59 mol) in dry dichloromethane (870 mL) at 0° C. was added carbon tetrabromide (100.86 g, 0.304 mol) portionwise. The mixture was stirred at RT for 30 min and then cooled to −78° C. A solution of tert-butyl 4-oxopiperidine-1-carboxylate (30 g, 0.15 mol) in CH2Cl2 (90 mL) was added dropwise and the reaction was stirred at −78° C. for 30 min and then at RT overnight. The mixture was filtered and the filtrate was evaporated to dryness. Diethyl ether was added and the mixture was filtered again. The filtrate was evaporated to dryness to give the title compound (64 g). 1H NMR (500 MHz, CDCl3): δ 3.44 (m, 4H), 2.46 (m, 4H), 1.47 (s, 9H).

Workup

  1. temperaturecooled to −78° C
  2. stirringthe reaction was stirred at −78° C. for 30 min
  3. customat RT
  4. customovernight
  5. filtrationThe mixture was filtered
  6. customthe filtrate was evaporated to dryness
  7. additionDiethyl ether was added
  8. filtrationthe mixture was filtered again
  9. customThe filtrate was evaporated to dryness

Sources & evidence

ORD record
ord-9bc8205664f945a08a7b88b5373d47c6
Source dataset
uspto-grants-2011_10
Patent number
US08044052B2

Reaction notes

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