Calcium Carbonate → HCID 21561658, compound

HRID 1581140Notes

Reaction equation

HRID 1581140 reaction equation
[N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][C:2]=1[NH:10]N1CCN=C1.[OH:16][S:17]([OH:20])(=O)=[O:18].O=S(=O)=O.C(=O)([O-])[O-].[Ca+2]>>[NH:3]1[CH2:4][CH2:5][N:1]=[C:2]1[NH:10][C:2]1[NH:1][C:5]2[CH:6]=[C:7]([S:17]([OH:20])(=[O:18])=[O:16])[CH:8]=[CH:9][C:4]=2[N:3]=1

Participants

4

Reactant 3

HCID 10112Calcium CarbonateHCID 24681Fuming sulfuric acidHCID 68130135HCID 68130135, compound

Product 1

HCID 21561658HCID 21561658, compound

Conditions

Temperature
100 °C

Procedure

2-(Benzimidazolylamino-2-imidazoline (5.00g) was treated cautiously with oleum (20 ml). The resulting solution was stirred and heated at 100°C for 11/2 hours. After cooling the solution was poured into ice/water (500 ml). Solid calcium carbonate was then added until the pH was 6.5. The white suspension was brought to the boil and the calcium sulphate filtered from the hot solution. The filtrate was concentrated under reduced pressure, brought to the boil again and filtered to remove a trace of insoluble material. The filtrate was acidified with glacial acetic acid and allowed to stand. A crystalline solid (3.98 g) separated on cooling. Recrystallisation from boiling water gave 2-(2-Imidazoline-2-ylamino)benzimidazole-5-sulphonic acid (1.16g) as colourless microcrystals. m.p. >360°C.

Workup

  1. temperatureAfter cooling the solution
  2. filtrationthe calcium sulphate filtered from the hot solution
  3. concentrationThe filtrate was concentrated under reduced pressure
  4. filtrationfiltered
  5. customto remove a trace of insoluble material
  6. customA crystalline solid (3.98 g) separated
  7. temperatureon cooling
  8. customRecrystallisation

Sources & evidence

ORD record
ord-cb49adae1acf41b8b992a5d9c1aa8472
Source dataset
uspto-grants-1976_01
Patent number
US03935314

Reaction notes

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