1H-BENZIMIDAZOLE-5-CARBOXYLIC ACID, 2,3-DIHYDRO-2-THIOXO-, METHYL ESTER synthesis

Yield:64375-41-3 74.5%

Reaction Conditions:

with potassium hydroxide in methanol;water at 76; for 5 h;

Steps:

1.4 Step 4: Methyl 2-thio-2,3-dihydro-1H-benzo[d]imidazole-5-carboxylate

Synthetic method: Methyl 3,4-diaminobenzoate (3g) was dissolved in methanol (75ml) and water (6ml), slowly added carbon disulfide (3.0ml) and KOH (3.9g), refluxed at 76 for 5h, TLC followed the reaction complete. The solvent was removed by rotary evaporation at 55°C, a small amount of water was added, the residue was dissolved with EA and extracted (100 mL×3), the combined EA phase was washed once with water (50 mL×1), once with saturated NaCl (30 mL), and the EA phase was dried over anhydrous sodium sulfate After dissolving in DCM and MeOH, dry sample column chromatography (DCM:MeOH 20:1) was obtained to obtain 2.8 g of white powdery solid, yield: 74.5%.

References:

CN111153891,2020,A Location in patent:Paragraph 0125; 0132; 0133