Hydrazine hydrate (1:1) → 6-Bromo-4,7-dimethyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-one

HRID 519223Notes

Reaction equation

HRID 519223 reaction equation
C([O:3][C:4](=O)[CH:5]([N:7]1[C:12]2[CH:13]=[C:14]([Br:18])[C:15]([CH3:17])=[CH:16][C:11]=2[O:10][CH2:9][C:8]1=S)[CH3:6])C.O.[NH2:22][NH2:23]>CCO>[Br:18][C:14]1[CH:13]=[C:12]2[C:11](=[CH:16][C:15]=1[CH3:17])[O:10][CH2:9][C:8]1[N:7]2[CH:5]([CH3:6])[C:4](=[O:3])[NH:22][N:23]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 867276272-(6-Bromo-7-methyl-3-thioxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester

Product 1

HCID 867276286-Bromo-4,7-dimethyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-oneYield 90.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 2-(6-bromo-7-methyl-3-thioxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester (0.192 g, 0.536 mmol) in EtOH (3 mL) was added anhydrous hydrazine hydrate (0.107 g, 2.144 mmol) and the mixture was heated at reflux for 4 h. The reaction mixture was cooled to ambient temperature and evaporated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 25% EtOAc in petroleum ether) to give 6-bromo-4,7-dimethyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-one as white solid (0.15 g, 90%). 1H NMR (DMSO-d6, 400 MHz): δ 10.80 (s, 1H), 7.46 (s, 1H), 7.02 (s, 1H), 4.86 (q, J=6.8 Hz, 1H), 4.60 (dd, J=12.8 Hz, 2H), 2.26 (s, 3H), 1.27 (d, J=6.8 Hz, 3H).

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux for 4 h
  3. customevaporated in vacuo
  4. customThe residue was purified by column chromatography on silica gel (eluting with 25% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-0ce4bac19af848e6aee2db6c9b1e7770
Source dataset
uspto-grants-2015_08
Patent number
US09115151B2

Reaction notes

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