Dimethylformamide → 4,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxamide

HRID 1066225Notes

Reaction equation

HRID 1066225 reaction equation
[CH3:1][C:2]1[O:3][C:4]2[C:10]3=[C:11]([S:17][CH3:18])[S:12][C:13]([C:14](O)=[O:15])=[C:9]3[CH2:8][CH2:7][C:5]=2[N:6]=1.C(Cl)(=O)C(Cl)=O.C[N:26](C)C=O>O1CCCC1>[CH3:1][C:2]1[O:3][C:4]2[C:10]3=[C:11]([S:17][CH3:18])[S:12][C:13]([C:14]([NH2:26])=[O:15])=[C:9]3[CH2:8][CH2:7][C:5]=2[N:6]=1

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 65578Oxalyl chlorideHCID 120435064,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylic acid

Product 1

HCID 120435104,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxamideYield 57%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

4,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylic acid (0.47 g) was suspended in tetrahydrofuran (15 ml); oxalyl chloride (0.32 g) and then N,N-dimethylformamide (6 μl) were added. After this mixture was stirred at room temperature for 2 hours, it was concentrated under reduced pressure. The residue was suspended in tetrahydrofuran (5 ml) and cooled with ice; concentrated aqueous ammonia (4.0 ml) was added. After the reaction mixture was stirred at room temperature for 1 hour, it was poured over water (150 ml) and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off to yield 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxamide (0.27 g, 57%), which was then recrystallized from chloroform-methanol. Light-yellow needles. Melting point over 300° C.

Workup

  1. concentrationit was concentrated under reduced pressure
  2. temperaturecooled with ice
  3. additionconcentrated aqueous ammonia (4.0 ml) was added
  4. stirringAfter the reaction mixture was stirred at room temperature for 1 hour
  5. additionit was poured over water (150 ml)
  6. extractionextracted with ethyl acetate-tetrahydrofuran (3:1
  7. washThe organic layer was washed with water
  8. dry with materialdried (MgSO4)
  9. distillationafter which the solvent was distilled off

Sources & evidence

ORD record
ord-0362daa83c4f48508c17d566daa29f4f
Source dataset
uspto-grants-2001_06
Patent number
US06242471B1

Reaction notes

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