Efficient synthesis of 1,3-benzodioxin-4-one and benzoxazine-2,4-diones

Abstract

Reactions of stable N-(o-hydroxyarylacyl)benzotriazoles 4a-c / 6a-c with various aldehydes in the presence of base afforded 1,3-benzodioxin-4-ones 1a-d and naphtho-1,3-dioxinones 7a-c. Reaction with isocyanates under similar conditions afforded high yields of benzoxazine-2,4-diones 2a-c and naphthoxazine-1,3-diones 9a-b.

Synthetic Utility of N-Acylbenzotriazoles

“…The Katritzky group exploited a practical route using benzotriazole-mediated methodology for an efficient and high yielding synthesis of 1,3-benzodioxin-4-ones 191 , 1,3-benzoxazine-2,4-diones 192 , naphtho-1,3-dioxinones 194 , and naphthoxazine-1,3-diones 195 (Scheme 66 ). 95 The reaction of N -( o -hydroxyarylcarbonyl)benzotriazoles 190 and 193 with various aldehydes in anhydrous THF as solvent in the presence of base furnished 1,3-benzodioxin-4-ones 191 and naphtho-1,3-dioxinones 194 , respectively at room temperature, whereas, under the similar reaction conditions, their reaction with suitable isocyanates produced 1,3-benzoxazine-2,4-diones 192 and naphthoxazine-1,3-diones 195 , respectively, in excellent yields. Both aromatic and aliphatic aldehydes and isocyanates were well tolerated as substrates in this methodology.…”

Synthesis of Heterocycles Mediated by Benzotriazole. 2. Bicyclic Systems

“…Treatment with isocyanates and triethylamine converts derivatives 784 into (3 H )-1,3-benzoxazin-2,4-diones 785 in 96–99% yields. Reactions of 784 with aldehydes provide 1,3-benzodioxin-4-ones 786 in 52–94% yields (Scheme ) …”

“…Reactions of 784 with aldehydes provide 1,3-benzodioxin-4-ones 786 in 52À94% yields (Scheme 169). 188 Addition of benzotriazole to the carbonyl groups of glyoxal provides quantitatively 1,2-bis(benzotriazol-1-yl)ethane-1,2-diol (787). 189 Treatment with thionyl chloride converts diol 787 into 1,2-dichloro derivative 788 in 90% yield.…”

1,2,3-Triazoles

“…Thus, in reactions with amines, compound 915 derived from 2-hydroxy-3-phenylpropionic acid gives amides 934 in 72–75% yield <2006JOC3364> . 1-Acylbenzotriazole 915 derived from salicylic acid reacts smoothly with amines to give salicylamides 935 <2006JOC3364> and with isocyanates to afford benzoxazine-2,4-diones 936 <2007ARK(vi)6> . Many other hydroxy carboxylic acids, with various distances between the hydroxy and carboxylic groups, produce similarly good results <2006JOC3364> .…”