Nitroethane → 1,2-Dimethoxy-4-(2-nitroprop-1-enyl)benzene
Reaction equation
COC1C=C(C=CC=1OC)C[C@@H](C)N.[CH3:15][O:16][C:17]1[CH:18]=[C:19]([CH:22]=[CH:23][C:24]=1[O:25][CH3:26])[CH:20]=O.[N+:27]([CH2:30][CH3:31])([O-:29])=[O:28]>>[CH3:15][O:16][C:17]1[CH:18]=[C:19]([CH:20]=[C:30]([N+:27]([O-:29])=[O:28])[CH3:31])[CH:22]=[CH:23][C:24]=1[O:25][CH3:26]Participants
Procedure
According to the present invention, (R)-3,4-dimethoxyamphetamine (3) is prepared according to the synthesis depicted in following Scheme I whereby the starting material 3,4-dimethoxy-benzaldehyde (veratric aidehyde) (10), which is a cheap raw material available from the market, is condensed with nitroethane (Henry's reaction), to form 3,4-dimethoxy-phenyl-2-nitropropene (11), which is then suitably reduced to an intermediate, i.e., 3,4-dimethoxy-phenyl-acetone (12) by means of a catalytic hydrogenation. The intermediate (12) is then reacted with an optically active amine, (R)-α-methyl-benzyl-amine (13) to form the corresponding chiral imine (14). In a key step of the present synthesis, the chiral amine (14) is diastereo-selectively reduced to the intermediate product, (R,R)-N-phenylethyl-3,4-dimethoxy-amphetamine (15) hydrochloride by catalytic hydrogenation with Raney-Nickel. The intermediate (15) is finally debenzylated by hydrogenation, to form (R)-3,4-dimethoxyamphetamine (3) hydrochloride. ##STR12##
Workup
- customis prepared
Sources & evidence
- ORD record
- ord-aa686d93869b4fe68a1f6392e1e39274
- Source dataset
- uspto-grants-1997_09
- Patent number
- US05663360
Reaction notes
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