Bromine → HCID 19100713, compound

HRID 1974975Notes

Reaction equation

HRID 1974975 reaction equation
[CH2:1]([C:3]1[C:11]2[NH:10][C:9](=[O:12])[C:8](=[O:13])[NH:7][C:6]=2[S:5][CH:4]=1)[CH3:2].C([O-])(=O)C.[Na+].[Br:19]Br.S(S([O-])=O)([O-])=O.[Na+].[Na+]>C(O)(=O)C>[Br:19][C:4]1[S:5][C:6]2[NH:7][C:8](=[O:13])[C:9](=[O:12])[NH:10][C:11]=2[C:3]=1[CH2:1][CH3:2]

Participants

6

Reactant 4

HCID 24408BromineHCID 24489Sodium DithioniteHCID 517045Sodium AcetateHCID 19100809HCID 19100809, compound

Product 1

HCID 19100713HCID 19100713, compoundYield 51.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

A suspension of 7-ethylthieno[2,3-b]pyrazine-2,3(1H,4H)-dione (1.0 g, 5.1 mmol) and sodium acetate (0.84 g, 10.2 mmol) in 225 ml of acetic acid was stirred at 10°-15° C. under a dry nitrogen atmosphere. A solution of bromine (0.26 ml, 5.1 mmol) in 2 ml of acetic acid was added during 0.5 h. Stirring was continued for further 0.5 h at room temperature and the reaction mixture was poured into ice water. The reddish mixture was decolourized by the addition of a small amount of aqueous sodium dithionite. The precipitate was filtered off, washed with water, resuspended in alcohol, filtered and washed with ether. Drying at 60° C. in vacuo afforded 720 mg (51%) of the title compound. M.p. 295°-297° C. 1H-NMR (DMSO-D6, δ): 1.04 (t, 3H), 2.62 (q, 2H), 12.01 (s, 1H), 12.19 (s, 1H).

Workup

  1. stirringStirring
  2. filtrationThe precipitate was filtered off
  3. washwashed with water
  4. filtrationfiltered
  5. washwashed with ether
  6. customDrying at 60° C. in vacuo

Sources & evidence

ORD record
ord-5ded666b6b5c45cb832fe514aa611ed2
Source dataset
uspto-grants-1994_02
Patent number
US05284847

Reaction notes

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