Sodium Carbonate → 2-Amino-6-chlorosulfonylbenzoxazole

HRID 736433Notes

Reaction equation

HRID 736433 reaction equation
[Cl:1][S:2]([OH:5])(=O)=[O:3].[NH2:6][C:7]1[O:8][C:9]2[CH:15]=[CH:14][CH:13]=[CH:12][C:10]=2[N:11]=1.S(Cl)(Cl)=O.C(=O)([O-])[O-].[Na+].[Na+]>C(OCC)(=O)C>[NH2:6][C:7]1[O:8][C:9]2[CH:15]=[C:14]([S:2]([Cl:1])(=[O:5])=[O:3])[CH:13]=[CH:12][C:10]=2[N:11]=1

Participants

6

Reactant 4

HCID 10340Sodium CarbonateHCID 207072-AminobenzoxazoleHCID 24386Thionyl ChlorideHCID 24638Chlorosulfonic acid

Product 1

HCID 589112872-Amino-6-chlorosulfonylbenzoxazoleYield 90%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

7.5 ml of chlorosulfonic acid was stirred at room temperature under an inert atmosphere. 5 g of 2-aminobenzoxazol (6-2) was added in small portions. The temperature was kept between 30-60° C. during the addition of 6-2. The mixture was heated to 80° C. for 2 hours. 5.3 g of thionyl chloride was added drop wise, keeping the temperature at 65° C. The mixture was stirred during 2 hours. After cooling to 0° C. 10 ml of ethyl acetate and 10 ml of a solution of sodium carbonate (1N) were added. The organic layer was separated from the water layer and this latter was extracted with ethyl acetate. The combined organic layers were dried over calcium chloride, yielding 7.8 g (90%) of 2-amino-6-chlorosulfonylbenzoxazole (6-3).

Workup

  1. additionThe temperature was kept between 30-60° C. during the addition of 6-2
  2. customat 65° C
  3. temperatureAfter cooling to 0° C
  4. customThe organic layer was separated from the water layer
  5. extractionthis latter was extracted with ethyl acetate
  6. dry with materialThe combined organic layers were dried over calcium chloride

Sources & evidence

ORD record
ord-e0204f6b207d4569b229862e317585a2
Source dataset
uspto-grants-2009_09
Patent number
US07595334B2

Reaction notes

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