Furfural → 2-Furfurylideneamino-4-methyl-5-methylsulfonylbenzoic acid
Reaction equation
[CH:1](=O)[C:2]1[O:6][CH:5]=[CH:4][CH:3]=1.[CH3:8][C:9]1[CH:10]=[C:11]([NH2:22])[C:12](=[CH:16][C:17]=1[S:18]([CH3:21])(=[O:20])=[O:19])[C:13]([OH:15])=[O:14]>>[CH:1](=[N:22][C:11]1[CH:10]=[C:9]([CH3:8])[C:17]([S:18]([CH3:21])(=[O:20])=[O:19])=[CH:16][C:12]=1[C:13]([OH:15])=[O:14])[C:2]1[O:6][CH:5]=[CH:4][CH:3]=1Participants
Conditions
- Temperature
- 80 °C
Procedure
This product is prepared by replacing the 2,4-dichloro-5-chlorosulfonylbenzoic acid employed in Example 1, Step A, by an equimolecular proportion of 4-methyl-5-chlorosulfonylanthranilic acid and then following substantially the same procedure described in Example 1, Steps A and B, there is obtained 4-methyl-5-methylsulfonylanthranilic acid employed in the following step without purification. The compound thus obtained is combined with excess furfural and heated on a water bath at about 80° C. The water formed during the reaction is removed by azeotropic distillation with the excess furfural at about 15 mm. Hg. pressure over a one hour period. The 2-furfurylideneamino-4-methyl-5-methylsulfonylbenzoic acid formed is stirred while cooling in acetic acid while a mixture of trimethylamine-borane complex in acetic acid is added over a 10 minute period. The reaction mixture then is heated on the steam bath for 5-10 minutes, then quenched in ice water to give 2-furfurylamino-4-methyl-5-methylsulfonylbenzoic acid.
Workup
- customemployed in the following step without purification
- customThe compound thus obtained
- customis removed by azeotropic distillation with the excess furfural at about 15 mm. Hg
Sources & evidence
- ORD record
- ord-6bf35b954a3b4790a4ae35e0783feafd
- Source dataset
- uspto-grants-1976_04
- Patent number
- US03953476
Reaction notes
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