Pyridine → 5-(2-Methoxyethylsulfonamido)-2-methylbenzoxazole
Reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([CH3:10])=[N:7][C:6]=2[CH:11]=1.N1C=CC=CC=1.[CH3:18][O:19][CH2:20][CH2:21][S:22](Cl)(=[O:24])=[O:23]>C(OCC)(=O)C>[CH3:18][O:19][CH2:20][CH2:21][S:22]([NH:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([CH3:10])=[N:7][C:6]=2[CH:11]=1)(=[O:24])=[O:23]Participants
Conditions
- Temperature
- 0 °C
Procedure
Into a 1.0 L round bottom flask equipped with mechanical stirrer, addition funnel, thermometer and nitrogen inlet tube was placed 100 grams (0.67 Mol) of 5-amino-2-methylbenzoxazole and 350 mL of pyridine. The slurry was stirred in an ice/ethanol bath at 0° C. then 110 grams (0.69 Mol) of Intermediate 1 was added dropwise so as to maintain a reaction temperature below 7° C. The reaction was stirred at 0° C. for two hours then the resulting red colored mixture was poured into 1.0 L of ethyl acetate. The slurry was stirred for 30 minutes then filtered and the collected solids were discarded. The filtrate was extracted with 4×200 mL of 10% hydrochloric acid and the organic phase was collected and dried over magnesium sulfate. The solvents were removed in vacuo to afford 140 grams (0.52 Mol, 76.7% yield) of desired product as a tan solid.
Workup
- customInto a 1.0 L round bottom flask equipped with mechanical stirrer, addition funnel
- customthermometer and nitrogen inlet tube was placed
- temperatureto maintain a reaction temperature below 7° C
- stirringThe reaction was stirred at 0° C. for two hours
- stirringThe slurry was stirred for 30 minutes
- filtrationthen filtered
- extractionThe filtrate was extracted with 4×200 mL of 10% hydrochloric acid
- customthe organic phase was collected
- dry with materialdried over magnesium sulfate
- customThe solvents were removed in vacuo
Sources & evidence
- ORD record
- ord-19827993b15d4df4943b33a9907b492b
- Source dataset
- uspto-grants-1991_10
- Patent number
- US05055387
Reaction notes
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