Method for preparing pyrrolidine derivatives
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsKanji Tomiya, Koichi Moriyasu, Harumichi Aoki, Kengo Oda
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Abstract
The present invention is directed to a method for preparing 3,4-trans-4-ethyl-1,3-disubstituted (substituted phenyl)pyrrolidine-2-one represented by the formula (1) ##STR1## which comprises the steps of dissolving 4-ethyl-1,3-disubstituted (substituted phenyl)-3-pyrroline-2-one in an inert solvent, and then reducing the same with sodium boron hydride in the presence of methanol.
Claims7
A method for preparing 3,4-trans-4-ethyl-1,3-disubstituted (substituted phenyl) pyrrolidine-2-one represented by the formula (1) ##STR10## wherein R.sup.1 is a hydrogen atom, halogen atom or methyl group;
- R.sup.2 is a hydrogen atom, alkyl group having 1 to 3 carbon atoms, alkoxy group having 1 to 4 carbon atoms, nitro group, cyano group, phenoxy group, hydroxyl group or halogen atom;
- X is a hydrogen atom, halogen atom, trifluoromethyl group, alkyl group having 1 to 3 carbon atoms, cyano group or nitro group;
- and n is 1 or 2 and denotes the number of substituents represented by X, and in the case of N=2, the substituents of X may be identical or different, but R.sup.1,R.sup.2 and Xn are not simultaneously hydrogen atoms, which comprises:
- reducing 4-ethyl-1,3-disubstituted (substituted phenyl)-3-pyrroline-2-one represented by the formula (2) ##STR11## wherein R.sup.1,R.sup.2, X and n are as defined above, with sodium boron hydride in the presence of methanol in an inert solvent.
A method for preparing 3,4-trans-4-ethyl-1,3-disubstituted(substituted phenyl)pyrrolidine-2-one, which comprises:
- 1) reacting 3,4-disubstituted aniline represented by formula (3) ##STR12## wherein R.sup.1 is a hydrogen atom, halogen atom or methyl group;
- and R.sup.2 is a hydrogen atom, alkyl group having 1 to 3 carbon atoms, trifluoromethyl group, haloalkoxy group having 1 to 3 carbon atoms, alkoxy group having 1 to 4 carbon atoms, nitro group, cyano group, phenoxy group, hydroxyl group or halogen atom, with a haloketone represented by formula (4) ##STR13## wherein Y is a halogen atom, to obtain a ketoaniline derivative represented by formula (5) ##STR14## wherein R.sup.1 and R.sup.2 are as defined above, 2) acylating the ketoaniline derivative with an Xn-substituted phenylacetyl halide to obtain a carbonyl derivative represented by formula (6) ##STR15## wherein R.sup.1 and R.sup.2 are as defined above, X is a hydrogen atom, halogen atom, trifluoromethyl group, alkyl group having 1 to 3 carbon atoms, cyano group or nitro group;
- and n is 1 or 2 and denotes the number of substituents represented by X, and in the case of n=2, the substituents of X may be identical or different, but R.sup.1,R.sup.2 and Xn are not simultaneously hydrogen atoms,
- 3) treating the carbonyl derivative with a base to carry out an intramolecular aldol condensation, thereby producing 4-ethyl-1,3-disubstituted(substituted phenyl)-3-pyrroline-2-one represented by formula (2) ##STR16## wherein R.sup.1,R.sup.2 X and n are defined above, and 4) reducing the 4-ethyl-1,3-disubstituted(substituted phenyl)-3-pyrroline-2-one with sodium boron hydride in the presence of methanol in an inert solvent, to obtain 3,4-trans-4-ethyl-1,3-disubstituted(substituted phenyl)pyrrolidine-2-one of formula (1) ##STR17## wherein R.sup.1,R.sup.2, X and n are as defined above.
Dependencies are inferred from the claim text.