Tetrahydrofuran → tert-Butyl 4-(bromomethylidene)piperidine-1-carboxylate

HRID 1666431Notes

Reaction equation

HRID 1666431 reaction equation
[Br:1][C:2](Br)=[C:3]1[CH2:8][CH2:7][N:6]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:5][CH2:4]1.C1COCC1.[Cl-].[NH4+]>CO.[Zn]>[Br:1][CH:2]=[C:3]1[CH2:8][CH2:7][N:6]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:5][CH2:4]1

Participants

6

Reactant 3

HCID 8028TetrahydrofuranHCID 25517Ammonium ChlorideHCID 53486134Tert-butyl 4-(dibromomethylene)piperidine-1-carboxylate

Product 1

HCID 45489892tert-Butyl 4-(bromomethylidene)piperidine-1-carboxylateYield 66.4%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 887MethanolSolvent

Procedure

tert-Butyl 4-(dibromomethylene)piperidine-1-carboxylate (64 g, 0.18 mol) was dissolved in methanol (438 mL) and THF (220 mL) and the solution was cooled to 0° C. Ammonium chloride (77.14 g, 1.44 mol) was added and the reaction was stirred for 30 min. Zinc dust (47.13 g, 0.72 mol) was added and the reaction mixture was stirred at RT for 2.5 h. The mixture was filtered and the filtrate was evaporated to dryness. The residue was purified by silica gel chromatography using 230-400 mesh silica gel (2% ethyl acetate in hexane) to give the title compound (33 g). 1H NMR (500 MHz, CDCl3): δ 5.99 (s, 1H), 3.40 (m, 4H), 2.38 (m, 2H), 2.23 (m, 2H), 1.47 (s, 9H).

Workup

  1. stirringthe reaction mixture was stirred at RT for 2.5 h
  2. filtrationThe mixture was filtered
  3. customthe filtrate was evaporated to dryness
  4. customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-d640c2f015594ded925c34275600eb31
Source dataset
uspto-grants-2011_10
Patent number
US08044052B2

Reaction notes

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