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

HRID 443827

Reaction equation

HRID 443827 reaction equation
[C:1]([O:10][CH3:11])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[NH2:4].ClOC(C)(C)C.ClNC1C(=CC=CC=1)C([O-])=O.[S:29]1[CH2:33][CH2:32][CH2:31][CH2:30]1>C(Cl)Cl.C(N(CC)CC)C>[NH2:4][C:3]1[C:5]([CH:30]2[CH2:31][CH2:32][CH2:33][S:29]2)=[CH:6][CH:7]=[CH:8][C:2]=1[C:1]([O:10][CH3:11])=[O:9]

Participants

7

Reactant 4

HCID 1127TetrahydrothiopheneHCID 8635Methyl AnthranilateHCID 521297Tert-Butyl hypochloriteHCID 23465897N-chloroanthranilate

Product 1

HCID 12713254Methyl 2-amino-3-(tetrahydro-2-thienyl)benzoate

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 8471TriethylamineSolvent

Procedure

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°.

Workup

  1. customat -70°
  2. temperatureto maintain the exotherm to less than 10°
  3. stirringthe solution is stirred for 24 hrs
  4. customThe solvents are removed
  5. additionthe residue is diluted with CH2Cl2
  6. washwashed with (1 N) NaOH solution, water
  7. customdried
  8. customRemoval of solvents
  9. customgives an oil
  10. customUnreacted methyl anthranilate is removed under reduced pressure (b.p. 95°-100°/0.35 mm) at bath temperature at 150°
  11. dissolutionThe residue is dissolved in CH 2 Cl2
  12. custompartially chromatographed through silica gel
  13. customThe solid residue is recrystallized from methanol

Sources & evidence

ORD record
ord-9fdd77b5cd204c609ca3cebe824ff70c
Source dataset
uspto-grants-1981_04
Patent number
US04261996

Linked notes

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