Gandhi Murugan

Simple and New Protocol for the Synthesis of Novel (z)-3-Arylidenebenzothiazepin-4-ones Using Baylis-Hillman Derivatives

Abstract A simple synthesis of novel (Z)-3-arylidene-2,3-dihydrobenzo[b][1,4]thiazepin-4(5H)-ones from bromo compounds derived from Baylis–Hillman adducts involving selective S-alkylation followed by a lactum formation has been described.

1-Methyl-3-(2-methyl-phen-yl)-3,3a,4,9b-tetra-hydro-1H-chromeno[4,3-c][1,2]oxazole-3a-carbonitrile.

In the title compound, C19H18N2O2, the five-membered isoxazole ring adopts an envelope conformation and the deviation of the N atom from the mean plane of the isoxazole ring is −0.3256 (11) Å. The pyran ring adopts a half-chair conformation. The isoxazole ring forms dihedral angles of 44.07 (7) and 84.23 (7)° with the pyran and methylbenzene rings, respectively. The molecular structure is stabilized by weak C—H⋯π interactions.

3-(3-Chloro­phen­yl)-1-methyl-3,3a,4,9b-tetra­hydro-1H-chromeno[4,3-c]isoxazole-3a-carbonitrile

In the title compound, C18H15ClN2O2, the five-membered isoxazole ring adopts an envelope conformation [the deviation of the N atom is 0.3154 (15) Å] and the six-membered pyran ring adopts a half-chair conformation. The mean plane through all atoms of the isoxazole ring forms dihedral angles of 47.98 (8)° with the mean plane of the chromene ring system and 75.10 (9)° with the chlorobenzene ring.

1-Methyl-3-(naphthalen-1-yl)-3,3a,4,9b-tetra-hydro-1H-chromeno[4,3-c]isoxazole-3a-carbonitrile.

In the title compound, C22H18N2O2, the pyran ring of the chromene unit is fused with an isoxazole ring, which adopts an N-envelope conformation with the N atom lying 1.3291 (14) Å from the mean plane of the remaining ring atoms [maximum deviation = 0.341 (2) Å]. The dihedral angle between the isoxazole and chromene units is 43.74 (8)° and that between the iosxazole ring and the naphthalene ring system is 58.82 (8)°. In the crystal, the molecules are linked by weak C—H⋯π interactions.

(E)-2-(2-Formyl-phen-oxy-meth-yl)-3-phenyl-prop-2-ene-nitrile.

In the title compound, C17H13NO2, the dihedral angle between the benzene and the phenyl ring is 65.92 (7)°. The carbonitrile side chain is almost linear, the C—C—N angle being 175.55 (14)°. The crystal structure is stabilized by intermolecular C—H⋯O interactions.

3-(2-Methyl-benzyl-idene)-2,3-dihydro-1,5-benzothia-zepin-4(5H)-one.

In the crystal structure of the title compound, C17H15NOS, the molecules form centrosymmetric dimers through pairs of N—H⋯O hydrogen bonds. The seven-membered ring adopts a distorted half-chair conformation.

Methyl 4'-(4-fluoro-phen-yl)-1'-methyl-3'-nitro-methyl-2-oxospiro-[indoline-3,2'-pyrrolidine]-3'-carboxyl-ate.

In the title compound, C21H20FN3O5, the the pyrrolidine ring makes dihedral angles of 84.91 (6) and 62.38 (7)° with the oxindole unit and the fluorophenyl ring, respectively. The pyrrolidine ring assumes an envelope conformation with the spiro C atom as the flap. The crystal packing features weak N—H⋯N and C—H⋯O hydrogen bonds.

Methyl 3-(4-fluoro-phen-yl)-1-methyl-1,2,3,3a,4,9b-hexa-hydro-chromeno[4,3-b]pyrrole-3a-carboxyl-ate.

In the title compound, C20H20FNO3, the pyrrolidine and benzopyran rings adopt half chair and twisted half chair conformations, respectively. The carboxylate group is almost perpendicular to the pyran ring [89.4 (1)°].