Pyrrolidine → tert-Butyl 6-bromo-4-oxo-3,4-dihydro-1'H-spiro[1,3-benzoxazine-2,4'-piperidine]-1'-carboxylate

HRID 518159Notes

Reaction equation

HRID 518159 reaction equation
[Br:1][C:2]1[CH:10]=[C:6]([C:7]([NH2:9])=[O:8])[C:5]([OH:11])=[CH:4][CH:3]=1.[C:12]([N:19]1[CH2:24][CH2:23][C:22](=O)[CH2:21][CH2:20]1)([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13].N1CCCC1>>[C:15]([O:14][C:12]([N:19]1[CH2:24][CH2:23][C:22]2([NH:9][C:7](=[O:8])[C:6]3[CH:10]=[C:2]([Br:1])[CH:3]=[CH:4][C:5]=3[O:11]2)[CH2:21][CH2:20]1)=[O:13])([CH3:18])([CH3:16])[CH3:17]

Participants

4

Reactant 3

HCID 31268PyrrolidineHCID 728765-BromosalicylamideHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylate2×

Product 1

HCID 2794762tert-Butyl 6-bromo-4-oxo-3,4-dihydro-1'H-spiro[1,3-benzoxazine-2,4'-piperidine]-1'-carboxylateYield 250.3%

Conditions

Temperature
72 °C

Procedure

Three batches of 5-bromo salicylamide (5.00 g each, 23.1 mmol), N-Boc-piperidin-4-one (3.45 g, 17.3 mmol) and pyrrolidine (1.64 g, 23.1 mmol) were heated in different flasks at 72° C. under MW irradiation for 1 h. Further N-Boc-piperidin-4-one (3.45 g, 17.3 mmol) was added and the mixtures were heated for 1 h at 72° C. The resulting precipitates were collected by filtration and washed with MeOH to give 6-bromo-3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,4′-piperidin]-1′-carboxylic acid tert-butyl ester (17.2 g) as a white solid.

Workup

  1. customThe resulting precipitates
  2. filtrationwere collected by filtration
  3. washwashed with MeOH

Sources & evidence

ORD record
ord-73ed22d84571453d84795820998ba510
Source dataset
uspto-grants-2015_08
Patent number
US09115148B2

Reaction notes

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