O-Phenylenediamine → Ethyl 4-(benzimidazol-2-yl)-3,3-dimethylbutanoate
Reaction equation
[CH3:1][C:2]([CH3:11])([CH2:7][C:8](O)=O)[CH2:3][C:4]([OH:6])=[O:5].[CH3:12][CH:13]=C(C)C.[C:17]1([NH2:24])[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=1[NH2:23].C(N(CC)CC)C>C(Cl)(Cl)Cl.O1CCCC1>[N:23]1[C:18]2[CH:19]=[CH:20][CH:21]=[CH:22][C:17]=2[NH:24][C:8]=1[CH2:7][C:2]([CH3:1])([CH3:11])[CH2:3][C:4]([O:6][CH2:12][CH3:13])=[O:5]Participants
Conditions
- Temperature
- 0 °C
Procedure
A solution of 139.2 g of the acid chloride ethyl ester of 3,3-dimethylglutaric acid, prepared in Example 28, in 125 ml of chloroform, stabilized with amylene, is added dropwise, at a temperature of between 5° C. and 10° C., to a solution of 72.8 g of orthophenylenediamine and 112 ml of triethylamine in 1 l of anhydrous tetrahydrofuran. The mixture is stirred at 0° C. for two hours and then at 50° C. for one hour; the crystals are filtered off and the solvents are evaporated off under vacuum. The residue is taken up in 4.4 l of ethanol and 444 l of concentrated hydrochloric acid and the mixture is refluxed for 12 hours. The solvents are evaporated off and the residue is taken up with water and then neutralized with a 1N solution of sodium hydroxide and extracted with ether. The ether phase is dried and then evaporated under vacuum to give 99 g of ethyl 4-(benzimidazol-2-yl)-3,3-dimethylbutanoate in the form of crystals melting at 123° C.
Workup
- waitat 50° C. for one hour
- filtrationthe crystals are filtered off
- customthe solvents are evaporated off under vacuum
- temperature444 l of concentrated hydrochloric acid and the mixture is refluxed for 12 hours
- customThe solvents are evaporated off
- extractionextracted with ether
- dry with materialThe ether phase is dried
- customevaporated under vacuum
Sources & evidence
- ORD record
- ord-05a436912ff74581a5958223410f0e50
- Source dataset
- uspto-grants-1992_06
- Patent number
- US05124336
Reaction notes
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