Methyl iodide → Methyl 5-(3-azidobutyl)thiophene-2-carboxylate
Reaction equation
O[CH:2]([CH3:13])[CH2:3][CH2:4][C:5]1[S:9][C:8]([C:10]([OH:12])=[O:11])=[CH:7][CH:6]=1.[CH3:14]I.C(=O)(O)[O-].[Na+].C1(C)C=CC(S(Cl)(=O)=O)=CC=1.[N-:32]=[N+:33]=[N-:34].[Na+]>CC(N(C)C)=O.N1C=CC=CC=1.CS(C)=O>[N:32]([CH:2]([CH3:13])[CH2:3][CH2:4][C:5]1[S:9][C:8]([C:10]([O:12][CH3:14])=[O:11])=[CH:7][CH:6]=1)=[N+:33]=[N-:34]Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 3
Procedure
For the preparation of the amine starting material of Example 7,4-(5-acetyl-2-thienyl)-2-butanone was reacted with ethylene glycol, triethyl o-formate and p-toluenesulfonic acid in methylene chloride selectively to give methyl 5-[2-(2-methyl-1,3-dioxolan-2-yl)ethyl]-2-thienyl ketone. Oxidation with sodium hypobromite and subsequent hydrolysis gave 5-(3-oxobutyl)-2-thiophenecarboxylic acid. With sodiumborohydride there was obtained therefrom 5-(3-hydroxy-butyl)-2-thiophenecarboxylic acid which was converted in dimethylacetamide with methyl iodide and sodium bicarbonate into the methyl ester. Treatment with p-toluene-sulfonyl chloride in pyridine and reaction with sodium azide in dimethylsulfoxide gave methyl 5-(3-azidobutyl)-2-thiophenecarboxylate from which the corresponding acid was obtained by saponification. With thionyl chloride there was prepared its acid chloride from which, with concentrated ammonia in diethyl ether, there was obtained 5-(3-azidobutyl)-2-thiophenecarboxamide. Reduction of the azido group with triphenylphosphine and subsequent hydrolysis gave (R,S)-5-(3aminobutyl)-2-thiophenecarboxamide, m.p. 65°-75°, ε256 =7780, ε275 =9900.
Sources & evidence
- ORD record
- ord-2e9bf4dfba0143708488c86a542b51c9
- Source dataset
- uspto-grants-1992_11
- Patent number
- US05166218
Reaction notes
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