Hydrochloric Acid → HCID 178527599, compound

HRID 1097129Notes

Reaction equation

HRID 1097129 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([S:9]([OH:12])(=[O:11])=[O:10])[CH:5]=[CH:6][C:7]=1[NH2:8].C([N:15]([CH2:18][CH3:19])[CH2:16][CH3:17])C.Cl>CO>[NH:8]1[C:7]2[CH:6]=[CH:5][C:4]([S:9]([OH:12])(=[O:10])=[O:11])=[CH:3][C:2]=2[N:1]=[C:17]1[C:16]1[NH:15][C:18]2[CH:19]=[CH:5][C:4]([S:9]([OH:12])(=[O:11])=[O:10])=[CH:3][C:2]=2[N:1]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 8471TriethylamineHCID 81986Benzenesulfonic acid, 3,4-diamino-

Product 1

HCID 178527599HCID 178527599, compoundYield 42%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
50 °C

Procedure

A round-bottom 3 neck flask was charged with 3,4-diaminobenzenesulfonic acid (8.0 g, 42.5 mmol) and anhydrous MeOH (0.85 L). O-Methyl-1,1,1-trichloroacetimidate was added (2.8 mL, 3.74 g, 21.2 mmol). The resultant suspension was stirred for 24 h at ambient conditions. Additional amount of O-methyl-1,1,1-trichloroacetimidate was added (1.4 mL, 1.87 g, 10.5 mmol) after this time, then reaction mixture was stirred for 72 h at ambient conditions, heated for 3 h at 50° C. and triethylamine (14 mL, 9.4 g, 93.5 mmol) was added. Stirring was continued at this temperature for 18 hours. Then reaction mixture was cooled to 30° C., and an intensive flow of dry HCl was passed through the solution until a precipitate was formed. The suspension was filtered off at 40° C., precipitate was washed with MeOH (4×150 mL, stirring of suspension for 10-15 min each turn) and with MeOH—HCl 3.5% solution (100 mL, 1 h of stirring). Product 1H,1′H-2,2′-bibenzimidazole-5,5′-disulfonic acid was pale yellow or colorless, weight 3.5 g, yield 42%. It may contain own hydrochloride as a salt. NMR 1H spectrum (Brucker Avance 300 instrument; solvent d6-dimethyl sulfoxide; δ, ppm; J, Hz): 5.27 br.s (—SO3H in exchange with H2O and NH) 7.73 m (2Ha, 2Hb), 8.01 br.s (2Hx). NMR 13C {1H} spectrum (Brucker Avance 300 instrument; solvent d6-dimethyl sulfoxide; δ, ppm): 113.00, 115.41, 123.27, 136.44, 137.60, 142.24, 145.34.

Workup

  1. customreaction mixture
  2. stirringStirring
  3. waitwas continued at this temperature for 18 hours
  4. customThen reaction mixture
  5. temperaturewas cooled to 30° C.
  6. customwas formed
  7. filtrationThe suspension was filtered off at 40° C.
  8. washprecipitate was washed with MeOH (4×150 mL
  9. stirringstirring of suspension for 10-15 min each turn) and
  10. stirringwith MeOH—HCl 3.5% solution (100 mL, 1 h of stirring)

Sources & evidence

ORD record
ord-26c567263901433d873c4772f49a1763
Source dataset
uspto-grants-2012_03
Patent number
US08142863B2

Reaction notes

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