Tetrahydrofuran → 2-(4-Methoxyphenylpropionyl)amino-6-n-propylamino-4,5,-6,7-tetrahydrobenzothiazole

HRID 703091Notes

Reaction equation

HRID 703091 reaction equation
O=[C:2]1[CH2:11][CH2:10][CH:5]2[NH:6][CH:7]([NH2:9])[S:8][C:4]2=[CH:3]1.[CH3:12][O:13][C:14]1[CH:19]=[CH:18][C:17]([CH2:20][CH2:21][C:22](Cl)=[O:23])=[CH:16][CH:15]=1.C([N:27]([CH2:30][CH3:31])CC)C.O1CCC[CH2:33]1>>[CH3:12][O:13][C:14]1[CH:19]=[CH:18][C:17]([CH2:20][CH2:21][C:22]([NH:9][C:7]2[S:8][C:4]3[CH2:3][CH:2]([NH:27][CH2:30][CH2:31][CH3:33])[CH2:11][CH2:10][C:5]=3[N:6]=2)=[O:23])=[CH:16][CH:15]=1

Participants

5

Reactant 4

HCID 8028TetrahydrofuranHCID 8471TriethylamineHCID 109324413-(4-Methoxyphenyl)propionyl chlorideHCID 695431246-Oxo-2-amino-tetrahydrobenzothiazole

Product 1

HCID 139847282-(4-Methoxyphenylpropionyl)amino-6-n-propylamino-4,5,-6,7-tetrahydrobenzothiazole

Procedure

15.1 g (0.09 mol) of 6-oxo-2-amino-tetrahydrobenzothiazole and 20.5 g (0.1-mol) of 4-methoxyphenylpropionyl chloride are refluxed for 2 hours in 450 ml of tetrahydrofuran and 0.1 mol of triethylamine, subsequently poured onto ice and extracted with ethyl acetate. After drying, 2-(4-methoxyphenylpropionyl)amino-6-oxo-tetrahydrobenzothiazole (17.5 g) crystallises out on concentrating, and, is dissolved in methanol and is reductively aminated, without further purification, in an autoclave using propylamine (Raney nickel, 5 bar, 60° C.). After filtering off the catalyst under suction, the solvent is removed by distillation. The residue crystallises from i-propyl ether. Yield: 12.5 g (63% of theory)

Workup

  1. extractionextracted with ethyl acetate
  2. customAfter drying
  3. custom2-(4-methoxyphenylpropionyl)amino-6-oxo-tetrahydrobenzothiazole (17.5 g) crystallises out
  4. concentrationon concentrating
  5. dissolutionis dissolved in methanol
  6. customis reductively aminated, without further purification, in an autoclave
  7. custompropylamine (Raney nickel, 5 bar, 60° C.)
  8. filtrationAfter filtering off the catalyst under suction
  9. customthe solvent is removed by distillation
  10. customThe residue crystallises from i-propyl ether

Sources & evidence

ORD record
ord-cda73363d12247cd9555d31201ec2b8c
Source dataset
uspto-grants-1991_01
Patent number
US04981862

Reaction notes

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