Reacción #531009

Ecuación de reacción

tetrahydrothiophene

methyl anthranilate

tert-butyl hypochlorite

N-chloroanthranilate

→

Methyl 2-amino-3-(tetrahydro-2-thienyl)benzoate

Disolventes

triethylamine

CH2Cl2

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroat -70°
2. 2
   Temperaturato maintain the exotherm to less than 10°
3. 3
   workup.STIRRINGthe solution is stirred for 24 hrs
4. 4
   OtroThe solvents are removed
5. 5
   workup.ADDITIONthe residue is diluted with CH2Cl2
6. 6
   Lavadowashed with (1 N) NaOH solution, water
7. 7
   Otrodried
8. 8
   OtroRemoval of solvents
9. 9
   Otrogives an oil
10. 10
    OtroUnreacted methyl anthranilate is removed under reduced pressure (b.p. 95°-100°/0.35 mm) at bath temperature at 150°
11. 11
    workup.DISSOLUTIONThe residue is dissolved in CH 2 Cl2
12. 12
    Otropartially chromatographed through silica gel
13. 13
    OtroThe solid residue is recrystallized from methanol

Procedimiento

A solution of methyl anthranilate (75.5 g; 0.5 mole) in CH2Cl2 (1.0 l) is cooled to -70° and a solution of tert-butyl hypochlorite (54 g; 0.5 mole) in CH2Cl2 (150 ml) is added slowly keeping the temperature at -70°. The resultant N-chloroanthranilate solution is stirred for 1.0 hr and then tetrahydrothiophene (110 ml) is added at such a rate as to maintain the exotherm to less than 10°. The dark solution is stirred at -70° for 2.0 hr, triethylamine (125 ml) is added dropwise, and the solution is stirred for 24 hrs. The solvents are removed and the residue is diluted with CH2Cl2, washed with (1 N) NaOH solution, water and dried. Removal of solvents gives an oil. Unreacted methyl anthranilate is removed under reduced pressure (b.p. 95°-100°/0.35 mm) at bath temperature at 150°. The residue is dissolved in CH 2 Cl2 and partially chromatographed through silica gel. The solid residue is recrystallized from methanol. Yield 27.0 g; mp 75°-9°.

Fuente