C(O[C:4]([C:6]1[N:7]2[CH:13]=[C:12]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=3[N+:20]([O-:22])=[O:21])[N:11]=[C:8]2[S:9][CH:10]=1)=O)C.[OH-:23].[Na+].C1[CH2:29][O:28]CC1.O>>[N+:20]([C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][C:14]=1[C:12]1[N:11]=[C:8]2[N:7]([CH:13]=1)[C:6]([CH2:4][C:29]([OH:28])=[O:23])=[CH:10][S:9]2)([O-:22])=[O:21]6-(2-Nitro-phenyl)-imidazo[2,1-b]thiazole-3-carboxylic acid ethyl ester (466 mg, 1.47 mmol) in 2:1 THF/Water was combined with 4 eq of NaOH (234 mg). The reaction mixture was heated to 50° C. for 3 hours. The reaction mixture was concentrated to dryness, the residue dissolved in water (20 ml), washed with CH2Cl2, and the aqueous layer was adjusted to pH=3 with 4N HCl. The solids were collected by filtration, washed with water and air dried to obtain the acid product was a brown solid (442 mg, 99% yield) (MS, M++H=304.0)
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