Oxalyl chloride → Tert-butyl 2-(5-bromobenzo[d]oxazole-2-carboxamido)-4-(4-chlorophenyl)thiophene-3-carboxylate

HRID 390776Notes

Reaction equation

HRID 390776 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([C:10]([OH:12])=O)=[N:7][C:6]=2[CH:13]=1.C(Cl)(=O)C(Cl)=O.[NH2:20][C:21]1[S:22][CH:23]=[C:24]([C:33]2[CH:38]=[CH:37][C:36]([Cl:39])=[CH:35][CH:34]=2)[C:25]=1[C:26]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27].CCN(C(C)C)C(C)C>C(Cl)Cl.CN(C=O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([C:10]([NH:20][C:21]3[S:22][CH:23]=[C:24]([C:33]4[CH:34]=[CH:35][C:36]([Cl:39])=[CH:37][CH:38]=4)[C:25]=3[C:26]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27])=[O:12])=[N:7][C:6]=2[CH:13]=1

Participants

7

Reactant 4

HCID 65578Oxalyl chlorideHCID 81531DiisopropylethylamineHCID 513585535-Bromo-1,3-benzoxazole-2-carboxylic acidHCID 59535972HCID 59535972, compound

Product 1

HCID 67207536Tert-butyl 2-(5-bromobenzo[d]oxazole-2-carboxamido)-4-(4-chlorophenyl)thiophene-3-carboxylate

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a suspension of 5-bromobenzo[d]oxazole-2-carboxylic acid (2A, 60 mg, 0.25 mmol) in DCM (5 ml) at room temperature was added oxalyl chloride (0.2 ml) and catalytic amount of DMF. The mixture was stirred at room temperature for 17 hours. The solvent was removed under vacuum to dryness. The residue was dissolved in DCM (5 ml) followed be addition of tert-butyl 2-amino-4-(4-chlorophenyl)thiophene-3-carboxylate (1A, 62 mg, 0.2 mmol) and DIEA (0.3 ml). The mixture was stirred at room temperature for 17 hours. The reaction mixture was diluted with DCM (5 ml) washed with 1N aqueous HCl (3×5 ml), water (1×5 ml), 1N aqueous NaOH (3×5 ml) and dried over anhydrous sodium sulfate. The drying agent was removed by filtration. The filtrate was concentrated under vacuum to give analytically pure 3A which was used in the next step without further purification. LC-MS: calcd. for C23H18BrClN2O4S: 532 (M+1); found: 532.

Workup

  1. customThe solvent was removed under vacuum to dryness
  2. dissolutionThe residue was dissolved in DCM (5 ml)
  3. stirringThe mixture was stirred at room temperature for 17 hours
  4. washwashed with 1N aqueous HCl (3×5 ml), water (1×5 ml), 1N aqueous NaOH (3×5 ml)
  5. dry with materialdried over anhydrous sodium sulfate
  6. customThe drying agent was removed by filtration
  7. concentrationThe filtrate was concentrated under vacuum

Sources & evidence

ORD record
ord-3b0d2e21ad254800a2ec7a92d960af6e
Source dataset
uspto-grants-2013_02
Patent number
US08383670B2

Reaction notes

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