8-(4-Tert-butoxycarbonyl-piperazin-1-yl)-6-chloro-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid benzyl ester → 4-(6-chloro-3,4-dihydro-2H-benzo[1,4]oxazin-8-yl)-piperazine-1-carboxylic acid tert-butyl ester

HRID 388277Notes

Reaction equation

HRID 388277 reaction equation
C(OC([N:11]1[C:16]2[CH:17]=[C:18]([Cl:34])[CH:19]=[C:20]([N:21]3[CH2:26][CH2:25][N:24]([C:27]([O:29][C:30]([CH3:33])([CH3:32])[CH3:31])=[O:28])[CH2:23][CH2:22]3)[C:15]=2[O:14][CH2:13][CH2:12]1)=O)C1C=CC=CC=1>C(O)C.[Pd]>[C:30]([O:29][C:27]([N:24]1[CH2:23][CH2:22][N:21]([C:20]2[C:15]3[O:14][CH2:13][CH2:12][NH:11][C:16]=3[CH:17]=[C:18]([Cl:34])[CH:19]=2)[CH2:26][CH2:25]1)=[O:28])([CH3:33])([CH3:31])[CH3:32]

Participants

4

Reactant 1

HCID 207656828-(4-Tert-butoxycarbonyl-piperazin-1-yl)-6-chloro-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid benzyl ester

Product 1

HCID 207656884-(6-chloro-3,4-dihydro-2H-benzo[1,4]oxazin-8-yl)-piperazine-1-carboxylic acid tert-butyl esterYield 71%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

A solution of 8-(4-tert-butoxycarbonyl-piperazin-1-yl)-6-chloro-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid benzyl ester (870 mg, 1.79 mmol) in ethanol (10 mL) was hydrogenated at atmospheric pressure over 10% Pd/C (75 mg) for 0.5 hour. The catalyst was removed by filtration, and the filtrate was concentrated. The crude material was purified by flash chromatography on silica gel (eluting with hexane-ethyl acetate; 1:1, v/v) to give 4-(6-chloro-3,4-dihydro-2H-benzo[1,4]oxazin-8-yl)-piperazine-1-carboxylic acid tert-butyl ester as a white foam (450 mg, 71%). MS: MH+=354.

Workup

  1. customThe catalyst was removed by filtration
  2. concentrationthe filtrate was concentrated
  3. customThe crude material was purified by flash chromatography on silica gel (
  4. washeluting with hexane-ethyl acetate

Sources & evidence

ORD record
ord-ef8bb09ce332446a8aaf2ddeb60d06f2
Source dataset
uspto-grants-2013_02
Patent number
US08377931B2

Reaction notes

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