Dimethyl 8-acetyl-2-methyl-1,2-dihydroquinoline-2,4-dicarboxylate

Abstract

Key indicators: single-crystal X-ray study; T = 296 K; mean (C-C) = 0.003 Å; R factor = 0.059; wR factor = 0.169; data-to-parameter ratio = 71.3.In the title compound, C 16 H 17 NO 5 , the six-membered Ncontaining ring has a half-boat form; the spiro C atom deviates by 0.34 (2) Å from the plane (r.m.s. deviation = 0.051 Å ) defined by the N and four aromatic C atoms. Intramolecular N-HÁ Á ÁO hydrogen bonding generates an S(6) ring motif and the dihedral angle between the mean plane though the S(6) ring and that through the five-atom half-boat plane is 3.39 (2) . In the crystal, weak intermolecular C-HÁ Á ÁO hydrogen bonds link molecules into zigzag chains along [001] due to c-glide symmetry, and C-HÁ Á Á interactions extend along [010].

An efficient method for the preparation of 2,2,4-trisubstituted 1,2-dihydroquinolines using catalytic amount Bi(OTf)3 as catalyst

“…23 Our experiments support the formation of enamines and imines but these intermediate products are rapidly transformed to product (4) in 54% yield (Scheme 1). The structures of 3a 24 , 3k 25 , 3o 26 , 3p 27 , 3l 28 and 3q 29 were determined by X-ray crystallography. When the same conditions were used with 2-chloro 3-amino pyridine, instead of the expected product (10), by-product (9) was produced in 23% yield (Scheme 2).…”