Sulfuric Acid → 2-ethyl-2,3-dihydro-1H-indene-2-carboxylic acid
Reaction equation
C[O:2][C:3]([CH:5]1[CH2:13][C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[CH2:6]1)=[O:4].[CH2:14]1C2C(=CC=CC=2)C[CH:15]1C(O)=O.S(=O)(=O)(O)O.C([N-]C1CCCCC1)(C)C.C(Br)C>>[CH2:14]([C:5]1([C:3]([OH:2])=[O:4])[CH2:13][C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[CH2:6]1)[CH3:15]Participants
Procedure
Second synthetic route disclosed in the same patent is following, as starting material was used 2,3-dihydro-1H-indene-2-carboxylic acid methyl ester, which was prepared by methylation of 2,3-dihydro-1H-indene-2-carboxylic acid in the presence of sulphuric acid. The 2,3-dihydro-1H-indene-2-carboxylic acid methyl ester was reacted with N-isopropylcyclohexylamide and ethylbromide yielding 2,3-dihydro-2-ethyl-1H-indene-2-carboxylic acid, then thionyl chloride was added and 2,3-dihydro-2-ethyl-1H-indene-2-carboxylic acid chloride was obtained. In the next step ethoxymagnesiummalonic acid ethyl ester in dry ether was added to 2,3-dihydro-2-ethyl-1H-indene-2-carboxylic acid chloride and reaction mixture was treated with sulphuric acid, and 1-(2,3-dihydro-2-ethyl-1H-inden-2-yl)ethanone was obtained, then the intermediate was stirred in methylene chloride and bromine was added by giving a new intermediate 2-bromo-1-(2,3-dihydro-2-methyl-1H-inden-2-yl)ethanone, to which was thereafter added formamide and hydrochloric acid yielding crude product of 5-(2-ethyl-2,3-dihydro-1H-inden-2-yl)-1H-imidazole. The last step involved hydrogenation of the crude product of 5-(2-ethyl-2,3-dihydro-1H-inden-2-yl)-1H-imidazole with 10% palladium on carbon.
Sources & evidence
- ORD record
- ord-94f89ab1aebe41d9ac2dd504683b7256
- Source dataset
- uspto-grants-2013_04
- Patent number
- US08431717B2
Reaction notes
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