Formaldehyde → 5-(Benzenesulphonylmethyl)-8-(furan-3-yl)-1,2-dihydro-benzo[d][1,3]oxazin-4-one
Reaction equation
[CH2:1]=O.[NH2:3][C:4]1[C:12]([C:13]2[CH:17]=[CH:16][O:15][CH:14]=2)=[CH:11][CH:10]=[C:9]([CH2:18][S:19]([C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)(=[O:21])=[O:20])[C:5]=1[C:6]([OH:8])=[O:7]>CO>[C:22]1([S:19]([CH2:18][C:9]2[C:5]3[C:6](=[O:8])[O:7][CH2:1][NH:3][C:4]=3[C:12]([C:13]3[CH:17]=[CH:16][O:15][CH:14]=3)=[CH:11][CH:10]=2)(=[O:21])=[O:20])[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=1Participants
4
Procedure
Formaldehyde (0.138 ml) was added dropwise to a solution of 2-amino-6-(benzenesulphonylmethyl)-3-(furan-3-yl)benzoic acid (Intermediate 211, 0.116 g) in methanol (4 ml) at 60° C. and the resultant mixture was stirred at that temperature for 0.5 hours. After cooling, the mixture was filtered through a phase separator and the filtrate was evaporated to dryness. The residue was triturated with diethyl ether and the solid was collected by filtration to give 5-(benzenesulphonylmethyl)-8-(furan-3-yl)-1,2-dihydro-benzo[d][1,3]oxazin-4-one (0.118 g) as a white solid.