An expedient sequential one-pot four component synthesis of novel steroidal spiro-pyrrolidine heterocycles in ionic liquid.

A facile one-pot synthesis of novel steroidal dispiro-indenoquinoxaline pyrrolidines via multicomponent-[3+2]-cycloaddition of azomethine ylides in ionic liquid is described. The structure of cycloadduct is confirmed by IR, (1)H NMR, (13)C NMR, high resolution mass spectroscopy and elemental analysis.

3-(Ferrocen-1-ylcarbon-yl)-1-methyl-4-(4-methyl-phen-yl)spiro-[pyrrolidine-2,11'-indeno-[1,2-b]quinoxaline].

In the title compound, [Fe(C(5)H(5))(C(32)H(26)N(3)O)], the pyrrolidine ring adopts a twist conformation. The indeno-quinoxaline ring system [86.44 (5)°], the methyl-phenyl ring [86.06 (7)°] and the ferrocene rings [82.00 (7) and 83.95 (9)°] are almost perpendicular to the pyrrolidine ring. The two cyclopentadienyl rings adopt an eclipsed conformation. The crystal structure features C-H⋯N inter-actions.

4-Ferrocenyl-1-methyl-3-benzoyl-spiro-[pyrrolidine-2,11'-indeno-[1,2-b]quinoxaline].

In the title compound, [Fe(C5H5)(C31H24N3O)], the pyrrolidine ring adopts a twist conformation. The pyrrolidine ring is almost perpendicular to the indeno-quinoxaline ring system, making a dihedral angle of 84.44 (5)°. The cyclo-penta-dienyl rings of the ferrocene moiety adopt an eclipsed conformation. The crystal packing features weak C-H⋯N and C-H⋯π inter-actions.

3'-Ferrocenylcarbon-yl-1'-methyl-4'-phenyl-spiro-[indeno-[2,3-b]quinoxaline-11,2'-pyrrolidine].

In the title compound, [Fe(C(5)H(5))(C(31)H(24)N(3)O)], the pyrrolidine ring makes a dihedral angle of 86.3 (3)° with the mean plane [r.m.s deviation = 0.074 (2) Å] of the indeno-quinoxaline ring system. The central pyrrolidine ring adopts a twist conformation and the two cyclopentadienyl rings adopt an eclipsed conformation. In the crystal, mol-ecules are linked by weak C-H⋯N and C-H⋯π inter-actions, propagating along the c and a axes, respectively.

1'-Methyl-3'-(4-methyl-benzo-yl)-4'-[5-(2-thien-yl)-2-thien-yl]spiro-[acenaphthyl-ene-1,2'-pyrrolidin]-2(1H)-one.

In the title compound, C(32)H(25)NO(2)S(2), the mean plane through the five-membered pyrrolidine ring, which exhibits an envelope conformation, makes dihedral angles of 82.3 (1) and 83.9 (9)° with the benzene ring and the acenaphthyl-ene ring system, respectively. The dihedral angle between the thiophene rings is 19.0(3)°. The crystal structure shows C-H⋯π and π-π inter-actions [centroid-centroid distance = 3.869 (2) Å].

3'-(4-Chloro-benzo-yl)-1'-methyl-4'-[5-(2-thien-yl)-2-thien-yl]spiro-[acenaphthyl-ene-1,2'-pyrrolidin]-2(1H)-one.

In the title compound, C(31)H(22)ClNO(2)S(2), the five-membered pyrrolidine ring, which exhibits an envelope conformation, makes a dihedral angle of 87.4 (2)° with the acenaphthyl-ene ring system. The crystal structure is stabilized by π-π inter-actions [centroid-centroid distance = 3.869 (2) Å]. A C atom and the S atom of the thiophene ring are disordered over two positions with refined occupancies of 0.629 (7) and 0.372 (7).