Triethylamine → Ethyl (2,6-dibromo-3-nitropyridin-4-yl)carbamate

HRID 639649Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 639649
Cl[C:2]([O:4][CH2:5][CH3:6])=[O:3].[Br:7][C:8]1[C:13]([N+:14]([O-:16])=[O:15])=[C:12]([NH2:17])[CH:11]=[C:10]([Br:18])[N:9]=1.C(N(CC)CC)C>O>[CH2:5]([O:4][C:2](=[O:3])[NH:17][C:12]1[CH:11]=[C:10]([Br:18])[N:9]=[C:8]([Br:7])[C:13]=1[N+:14]([O-:16])=[O:15])[CH3:6]

Komponenten

5

Edukt 3

HCID 8471TriethylamineHCID 10928Ethyl chloroformate2×HCID 532497652,6-Dibromo-3-nitropyridin-4-amine

Produkt 1

HCID 86614481Ethyl (2,6-dibromo-3-nitropyridin-4-yl)carbamateAusbeute 67,6 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Versuchsvorschrift

A solution of ethyl chloroformate (5.96 g) in anhydrous 2-methyl THF (50 ml) was added drop-wise to a solution of 2,6-dibromo-3-nitro-pyridin-4-ylamine (15.00 g) and triethylamine (10.1 g) in anhydrous 2-methyl THF (100 ml) at 0° C., keeping the addition rate such that the reaction temperature did not rise above 5° C. The reaction mixture was allowed to warm to room temperature then left to stir under nitrogen for 1 hour. A further portion of ethyl chloroformate (0.54 g) was added and the mixture was left to stir for a further 1 hour. Water (50 ml) was added and the layers separated. The aqueous layer was extracted with EtOAc (50 ml) and the combined organics were dried (MgSO4) and evaporated to a brown solid. This solid was pre-absorbed onto silica (˜19 g) then columned on Isco Companion on a silica column (330 g, Redisep), eluting with EtOAc:heptane. The gradient was kept isocractic at 10:90 for 1 column volume (CV), then increased linearly from 10:90 to 30:70 over 6 CVs. This provided the title compound (12.6 g) as a pale yellow foamy solid.

Aufarbeitung

  1. customdid not rise above 5° C
  2. waitthen left
  3. waitthe mixture was left
  4. stirringto stir for a further 1 hour
  5. customthe layers separated
  6. extractionThe aqueous layer was extracted with EtOAc (50 ml)
  7. dry with materialthe combined organics were dried (MgSO4)
  8. customevaporated to a brown solid
  9. customThis solid was pre-absorbed onto silica (˜19 g)
  10. washeluting with EtOAc
  11. temperatureincreased linearly from 10:90 to 30:70 over 6 CVs

Quellen und Nachweise

ORD-Eintrag
ord-dea40a0a5fab44f3b83f7284a31f8ddc
Quelldatensatz
uspto-grants-2010_04
Patentnummer
US07691877B2

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