A Green and Sustainable Approach for Selective Halogenation of Anilides, Benzanilides, Sulphonamides and Heterocycles^†

Abstract

An efficient green and sustainable protocol has been devised for the selective oxidative halogenation of acetanilides, benzanilides, sulphonamides, and heterocyclic compounds, using easily available NaX as a halogen source and Oxone as a powerful oxidant. Reaction products were analyzed by GC-MS. Defined experimental conditions provided the mono and dihalo compounds. The present protocol is simple and environmentally benign to conduct the laboratory scale halogenations and can be extended to prepare industrially important compounds.[a] V. M.

From Reactive Oxygen Species to Reactive Brominating Species: Fenton Chemistry for Oxidative Bromination

“…With the discovery and optimized conditions of in situ RBS generation from FeBr 2 –H 2 O 2 and CeBr 3 –H 2 O 2 , we set out to expand the scope of arene bromination ,,− (Table -1). Brief examination of the substrate scope revealed that only electron-rich arenes were suitable for bromination to provide p -bromoarene products ( 2a – 2g ) in 52–97% yields ( p : o > 20:1) (Table -1).…”

Antibacterial Spiropyrimidinetriones with N-Linked Azole Substituents on a Benzisoxazole Scaffold Targeting DNA Gyrase

“…For the syntheses of 11u and 11w (each a pair of diastereomers), the R 5 substituent was also transformed from one entity to another, designated in Scheme as 6d (R 5 substituent) being transformed to 6b (R 5 ′ substituent). Only a few examples exist in the literature for the chlorination of triazole 5-position anions , and for the nucleophilic displacement of similarly positioned 5-chlorotriazoles. − The intermediates 6a–d were converted to 11a–w by heating with barbituric acid under aqueous acid conditions, during which deprotection of the ketal occurred in situ, releasing the aldehyde for the T-reaction. Overall, the versatility of the sequences in Scheme permitted the selective substitution at either 3- or 5-position of the triazole.…”

Selective Oxidation of Clopidogrel by Peroxymonosulfate (PMS) and Sodium Halide (NaX) System: An NMR Study

“…Like other green oxidants such as O 2 and H 2 O 2 [ 5 ], peroxymonosulfate (PMS, Oxone ® ) has been widely used: (1) in the academia to develop new synthetic protocols [ 6 ]; (2) in pharmaceutical companies to promote oxidative stress testing of active pharmaceutical ingredients (API) to predict their degradation [ 7 ]; and (3) in hypersaline industrial wastewaters to remove organic contaminants [ 8 , 9 , 10 ]. This safe, sustainable, and inexpensive oxidant has shown extraordinary reactivity with alkaline metal halide salts [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ] and with hydrogen halides (HCl, HBr and HI) [ 28 , 29 , 30 ].…”