Reactions of o‐bromoacetylacylphenones with several primary amines

Abstract

o‐Monobromoacetylacylphenones, 3a and 3b reacted with hydroxylamine or hydrazine hydrate to produce heterocycles, 2,3‐benzoxazine or phthalazine derivatives. The reaction of bromoacetyl group of 3a and 3b with several thioamides afforded thiazole derivatives in high yields. Whereas o‐dibromoacetyl‐benzophenoe 2a reacted with aniline or cyclohexylamine to produce non‐heterocycles, 2‐substituted‐iminophenylindanones and the mechanism for the formation of these non‐heterocycles is proposed.

A Simple and Efficient Synthesis of Ethyl 1‐Aryl‐4‐formyl‐1H‐pyrazole‐3‐carboxylates

“…Aromatic or heteroaromatic compounds possessing two carbonyl groups in the ortho‐positions are versatile building blocks for the synthesis of condensed heterocycles such as fused [ c ]furans [14], [ c ]thiophenes [15], [ c ]pyrroles [16], and [ d ]oxazines [17]. We have also studied some properties of the compounds 4 .…”

Palladium‐Catalyzed Regioselective Acylation of Diazines with Toluenes: A New Approach to the Synthesis of ortho‐Diacylbenzenes

“…For instance, benzophenone derivatives are proven to be of use in treating immune deficiency disease . Markably, ortho ‐diacylbenzenes are important intermediates for the synthesis of biologically and pharmaceutically active compounds, such as phthalazines, dioximes, isoindoles, isobenzofurans, isoquinolines, anthracene derivatives, indanones and isoindolines (Scheme ). Ortho ‐diacylbenzenes are also used as fluorescent reagents for amino acids and peptide analysis…”

Uncatalyzed One-Pot Synthesis of Highly Substituted Pyridazines and Pyrazoline-Spirooxindoles via Domino SN/Condensation/Aza-ene Addition Cyclization Reaction Sequence

“…Pyridazines and fused pyridazines with their reduced derivatives are important subclasses of diaza-six-membered heterocycles that possess synthetic utility − and important pharmacological activities. , Several biologically active natural and unnatural compounds consist of heterocycles containing an N–N bond in six membered rings such as well-known piperazic acid and 1-Azafagomine. − In this class of compounds, 1,4-dihydropyridazines are of particular interest because of their activities as cardiovascular and spasmolytic agents that can be correlated with those of 1,4-dihydropyridine. , Conventional methods for pyridazine synthesis are based on the reaction of hydrazine or its derivatives with 1,4-dicarbonyls − and different types of [2 + 4] hetero Diels–Alder reaction. − Synthetic methods based on Ugi four-component reaction and electrophilic hydrazination of enolates − are most interesting recent methods for the preparation of 1,4-dihydropyridines.…”