Pentyl nitrite → Ethyl benzo[d]thiazole-6-carboxylate

HRID 1498956Notes

Reaction equation

HRID 1498956 reaction equation
N[C:2]1[S:3][C:4]2[CH:10]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:8]=[CH:7][C:5]=2[N:6]=1.N(OCCCCC)=O>O1CCCC1>[S:3]1[C:4]2[CH:10]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:8]=[CH:7][C:5]=2[N:6]=[CH:2]1

Participants

4

Reactant 2

HCID 10026Pentyl nitrite3×HCID 601008Ethyl 2-Aminobenzothiazole-6-carboxylate

Product 1

HCID 10512520Ethyl benzo[d]thiazole-6-carboxylateYield 70.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Ethyl 2-aminobenzothiazole-6-carboxylate (7.78 g, 35.0 mmol) prepared in the Step 36-1-1 was dissolved in tetrahydrofuran (100 ml). Amyl nitrite (8.2 g, 70.0 mmol) was added thereto, and the mixture was heated under reflux. After 1.5 hours, amyl nitrite (3.5 g, 30.0 mmol) was added thereto, and the resulting mixture was heated under reflux. After another 0.5 hours, amyl nitrite (2.6 g, 22.3 mmol) was added thereto, and the resulting mixture was heated under reflux. After being heated under reflux for another 3 hours, the resulting mixture was concentrated under a reduced pressure. The concentrate was purified by silica gel column chromatography (chloroform:methanol=100:1-20:1, and then n-hexane:ethyl acetate=3:1) to give the title compound (5.1 g, 70%) as a light-brown powder.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux
  3. temperaturethe resulting mixture was heated
  4. temperatureunder reflux
  5. waitAfter another 0.5 hours
  6. temperaturethe resulting mixture was heated
  7. temperatureunder reflux
  8. temperatureAfter being heated
  9. temperatureunder reflux for another 3 hours
  10. concentrationthe resulting mixture was concentrated under a reduced pressure
  11. customThe concentrate was purified by silica gel column chromatography (chloroform

Sources & evidence

ORD record
ord-c2a883aa4b4f45db989798a1888ea5e5
Source dataset
uspto-grants-2015_12
Patent number
US09200008B2

Reaction notes

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