Ethyl orthoformate → 2-[6-(4-Methyl-piperazin-1-ylmethyl)-benzoimidazol-1-yl]-4-phenyl-thiazole-5-carboxylic acid ethyl ester
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[S:10][C:9]([NH:11][C:12]2[CH:17]=[C:16]([CH2:18][N:19]3[CH2:24][CH2:23][N:22]([CH3:25])[CH2:21][CH2:20]3)[CH:15]=[CH:14][C:13]=2[NH2:26])=[N:8][C:7]=1[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)=[O:5])[CH3:2].[CH:33](OCC)(OCC)OCC>C(O)(=O)C>[CH2:1]([O:3][C:4]([C:6]1[S:10][C:9]([N:11]2[C:12]3[CH:17]=[C:16]([CH2:18][N:19]4[CH2:20][CH2:21][N:22]([CH3:25])[CH2:23][CH2:24]4)[CH:15]=[CH:14][C:13]=3[N:26]=[CH:33]2)=[N:8][C:7]=1[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)=[O:5])[CH3:2]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a mixture of 2-[2-amino-5-(4-methyl-piperazin-1-ylmethyl)-phenylamino]-4-phenyl-thiazole-5-carboxylic acid ethyl ester (VII.1a) from previous step and 0.2 mL of acetic acid was added 0.2 mL of triethyl orthoformate. The reaction mixture was heated to 60 degrees for 1 hour, and then concentrated under reduced pressure. The residue was diluted with 10 mL of water and 2 mL of saturated sodium bicarbonate and then extracted three times with 5 mL of dichloromethane. The combined organic layers were washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with methanol-dichloromethane (gradient 0:100-10:90) to give 0.041 g of 2-[6-(4-methyl-piperazin-1-ylmethyl)-benzoimidazol-1-yl]-4-phenyl-thiazole-5-carboxylic acid ethyl ester (I.1a) as a white solid.