Indene → Tert-butyl Spiro[indene-1,4'-piperidine]-1'-carboxylate

HRID 1587676Notes

Reaction equation

HRID 1587676 reaction equation
[CH2:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[C:20]([O:24][C:25]([N:27]([CH2:31][CH2:32]Cl)[CH2:28][CH2:29]Cl)=[O:26])([CH3:23])([CH3:22])[CH3:21]>O1CCCC1>[C:20]([O:24][C:25]([N:27]1[CH2:31][CH2:32][C:1]2([C:9]3[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=3)[CH:3]=[CH:2]2)[CH2:29][CH2:28]1)=[O:26])([CH3:23])([CH3:22])[CH3:21]

Participants

5

Reactant 3

HCID 7219IndeneHCID 2733832Lithium HexamethyldisilazideHCID 11230235N-BOC-N,N-Bis(2-chloroethyl)amine

Product 1

HCID 3653579Tert-butyl Spiro[indene-1,4'-piperidine]-1'-carboxylateYield 62.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

To a solution of indene (5.1 ml, 0.04 mol) in dry tetrahydrofuran (15 ml), cooled in an ice bath and maintained under an atmosphere of nitrogen, was added lithium bis (trimethylsilyl) amide (82 ml of a 1.0M solution in tetrahydrofuran, 0.08 mol), over 15 minutes. The mixture was stirred in the cold for 30 minutes, then added dropwise to a solution of N-tert-butyloxycarbonylbis (2-chloroethyl)amine (9.9 g, 0.04 mol) in tetrahydrofuran (200 ml), at 0° C. The mixture was stirred for 2 hours at this temperature, then allowed to warm to ambient temperature and stirred for a further 30 minutes. The solvent was removed in vacuo to leave a dark oil, which was chromatographed using 5:1 petrol:ether as the eluant, to give 1'-(tert-butyloxycarbonyl)spiro[indene-1,4'-piperidine] (7.1 g, 58%) as a pale yellow solid. N.M.R. (CDCl3)δ 1.28 (2H, d, J=12 Hz), 1.50 (9H, s), 2.00 (2H, t of d, J=12 and 4 Hz), 3.13 (2H, t of d, J=12 and 2 Hz), 4.20 (2H, m), 6.79 (1H, d, J=6 Hz), 6.84 (1H, d, J=6 Hz), 7.30 (4H, m).

Workup

  1. temperaturemaintained under an atmosphere of nitrogen
  2. stirringThe mixture was stirred for 2 hours at this temperature
  3. stirringstirred for a further 30 minutes
  4. customThe solvent was removed in vacuo
  5. customto leave a dark oil, which
  6. customwas chromatographed

Sources & evidence

ORD record
ord-d7abb23e872344b9974521e8eaa9d791
Source dataset
uspto-grants-1993_06
Patent number
US05219860

Reaction notes

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