Synthesis and Crystal Structures of Methyl 3-(Benzoylamino)-6-methyl-2-oxo-2H-pyran-5-carboxylate and N-[5-(3,4-Dimethoxyphenyl)-6-methyl-2-oxo-2H-pyran-3-yl]benzamide

Abstract

The compounds methyl 3-(benzoylamino)-6-methyl-2-oxo-2H-pyran-5-carboxylate (1), C 15 H 13 NO 5 , and N-[5-(3,4-dimethoxyphenyl)-6-methyl-2-oxo-2H-pyran-3-yl] benzamide (2), C 21 H 19 NO 5 , crystallize as a centrosymmetric hydrogen-bonded dimer facilitated by N-HÁÁÁO interactions involving the amide and carbonyl moiety of the lactone group of adjacent molecules. Supramolecular aggregation in 1 is controlled by a combination of p-p interactions [centroid-centroid distance = 4.0745(11) Å ] and weak C-HÁÁÁO hydrogen bonding between the phenyl ring of the benzoylamino group and the carbonyl atom of the methoxycarbonyl group and in 2 by a combination of p-p interactions [centroidcentroid distance = 4.0699(8) and 4.1556(10) Å ], weak C-HÁÁÁO interactions between the methoxy substituents of the adjacent dimethoxyphenyl group and weak C-HÁÁÁ p interactions.

Synthesis and Structural Evaluation of 5-Methyl-6-acetyl Substituted Indole and Gramine

“…[16][17][18][19][20][21] Here we applied (Z)-1-methoxybut-1-en-3-yne (4) as the dienophile cycloadding on 2H-pyran-2-one derivative 3 yielding a crucial intermediate 5, a substituted N-{2-[(Z)-2-methoxyethenyl]phenyl}benzamide (Scheme 1). This intermediate 5 has a strategically positioned methoxy group bound to the ethenyl fragment being in an ortho position to the benzamido group, therefore enabling a straightforward cyclization towards the indole ring (i.e.…”