Methyl acetoacetate → Methyl 5-(2-nitrophenyl)-3-oxopent-4-enoate
Reaction equation
[N+:1]([C:4]1[CH:11]=[CH:10][CH:9]=[CH:8][C:5]=1[CH:6]=O)([O-:3])=[O:2].[C:12]([O:18][CH3:19])(=[O:17])[CH2:13][C:14]([CH3:16])=[O:15].C(O)(=O)C.N1CCCCC1>>[CH3:19][O:18][C:12](=[O:17])[CH2:13][C:14]([CH:16]=[CH:6][C:5]1[CH:8]=[CH:9][CH:10]=[CH:11][C:4]=1[N+:1]([O-:3])=[O:2])=[O:15]Participants
4
Procedure
In the first step of the synthesis 2-nitro-benzaldehyde is reacted with methyl acetoacetate in the presence of a catalytic amount (0.01-0.7 mole, related to 1 mole of methyl acetoacetate) of piperidine acetate to give methyl-2-nitro-benzylidene-acetoacetate with a high yield of about 97%. This product is reacted after or without isolation with methyl-3-amino-crotonate. The yield of the second step is 87%, the total yield of both steps amounts to 84.4%. According to the disclosure of the cited Hungarian patent the thin layer chromatogram of the nifedipine thus obtained shows no by-products (Merck-type plate coated with kieselgel; developed with a 3:2:5 mixture of chloroform, acetone and petrolether).
Sources & evidence
- ORD record
- ord-7af96c28d1db40d9890fcc8d5103e651
- Source dataset
- uspto-grants-1992_06
- Patent number
- US05126457
Reaction notes
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