13444-14-9Relevant academic research and scientific papers
The Reaction of Dialkyl Carbonates with o-Aminophenol Catalysed by K 2CO3: A Novel High-Yield Synthesis of N-Alkylbenzoxazol-2- ones
Selva, Maurizio
, p. 2872 - 2876 (2003)
At 130-150°C and in the presence of catalytic K2CO 3, o-aminophenol (1) readily reacts with dialkyl carbonates (2: ROCO2R; 2a: R = Me, 2b: Et, 2c: Allyl, 2d: Bn) to give the corresponding N-alkylbenzoxazol-2-ones (3a-d) in high yields (88-98%). This reaction is a rare example where dialkyl carbonates may simultaneously act as carbonylating and alkylating agents likely through a BAc2/B A12 sequence. Moreover, compounds 2a-c serve also as solvents. In the case of 2d, 1,2-dimethoxyethane (DME) is the reaction medium.
Palladium-Catalyzed Dehydrative Cross-Coupling of Allylic Alcohols and N-Heterocycles Promoted by a Bicyclic Bridgehead Phosphoramidite Ligand and an Acid Additive
Kang, Kyungjun,Kim, Jaewook,Lee, Ansoo,Kim, Woo Youn,Kim, Hyunwoo
, p. 616 - 619 (2016)
A mild and efficient dehydrative cross-coupling reaction between allylic alcohols and N-heterocycles using palladium catalysis is reported. A bicyclic bridgehead phosphoramidite (briphos) ligand together with Pd(dba)2 is a highly efficient catalyst, and an acid additive involved in the rate-determining step promotes the catalytic cycle. The coupling reaction of allylic alcohols with N-heterocycles including imidazoles, benzimidazoles, and triazole proceeds under mild reaction conditions with high yields using Pd/briphos and pentafluorophenol.
Synthesis of 3-alkylbenzoxazolones from N-alkyl-N-arylhydroxylamines by contiguous O-trichloroacetylation, trichloroacetoxy ortho-shift, and cyclization sequence
Ram, Ram N.,Soni, Vineet Kumar
, p. 11935 - 11947 (2014/01/06)
Benzoxazolone pharmacophore is present in clinical pharmaceuticals, drug candidates, and many compounds having a wide spectrum of biological activities. The methods available for the synthesis of benzoxazolones have limited diversity due to problems in accessibility and air-sensitivity of diversely substituted o-aminophenols from which they are generally prepared by cyclocarbonylation with phosgene or its equivalents. The present paper describes a mild method for the synthesis of 3-alkylbenzoxazolones from easily accessible and air-stable nitroarenes. Nitroarenes were converted to N-alkyl-N-arylhydroxylamines in two steps involving partial reduction to arylhydroxylamines followed by selective N-alkylation. Treatment of N-alkyl-N-arylhydroxylamines with trichloroacetyl chloride and triethylamine afforded 3-alkylbenzoxazolones generally in good yields through an uninterrupted three-step sequence involving O-trichloroacetylation, N→Cortho trichloroacetoxy shift, and cyclization in a single pot at ambient temperatures. The present method is mild, wide in scope, economical, and regioselective. Many sensitive groups like alkyl and aryl esters, amide, cyano, and the carbon-carbon double bond survive the reaction.
