[O:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([OH:8])=O.[NH2:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]2[S:17][C:18]3[CH:24]=[C:23]([CH3:25])[CH:22]=[CH:21][C:19]=3[N:20]=2)=[CH:12][CH:11]=1.CN1CCOCC1.O.ON1C2C=CC=CC=2N=N1>C(Cl)Cl>[O:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([NH:9][C:10]1[CH:11]=[CH:12][C:13]([C:16]2[S:17][C:18]3[CH:24]=[C:23]([CH3:25])[CH:22]=[CH:21][C:19]=3[N:20]=2)=[CH:14][CH:15]=1)=[O:8]First Route: 2-Furoic acid (1.85 gms, 16.5 mmole) was dissolved in anhydrous methylene chloride (30 mls), to which solution was added a suspension of 2-(4-amino-phenyl)-6-methyl benzothiazole (4.76 g., 16.5 mmole) and N-methyl morpholine (2.0 g., 16.5 mmole) in methylene chloride (30 mls, at room temperature). Then, 1-hydroxy-benzotriazole hydrate (2.67 g., 16.5 mmole) and 1-(3-dimethyl amino propyl)-3-ethyl carbodiimide hydrochloride (4.75 g., 16.5 mmole) were added at room temperature. More methylene chloride (20 ml.) was added with stirring at room temperature, and the reaction maintained overnight. The initial clear reaction solution changed to a turbid solution. More methylene chloride (10 ml.) was added to the product mixture, which was then extracted with 1N HCl to separate a solid. The solid was filtered and washed with water. The product solid was crystallized from large amount of MeOH to yield 2.19 gm. (33.1%). mp. 238-240° C. 1H and 13C NMR were consistent with the expected product. TLC showed one spot (5% MeOH—CH2Cl2 as developing solvent on silica gel plate).
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