Synthesis by microwave irradiation of a substituted benzoxazine parallel library with preferential relaxant activity for guinea pig trachealis

Ring Opening of 2‐(Benzylamino)‐2H‐1,4‐benzoxazin‐3(4H)‐ones and 2‐Bromo‐2H‐1,4‐benzoxazin‐3(4H)‐ones

“…solvents were prepared according to literature procedures [14]. 4-Methyl-7-nitro-2H-1,4-benzoxazin-3(4H)-one and ethyl 4-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-7-carboxylate were synthesized from the corresponding 2-aminophenols and chloroacetyl chloride (ClCH 2 COCl) by analogy to published procedures [15]. Anal.…”

Tandem Ugi MCR/Mitsunobu Cyclization as a Short, Protecting‐Group‐Free Route to Benzoxazinones with Four Diversity Points

“…Scheme 1. Benzo [b] [1,4]oxazin-3-ones represent a typical drug-like structure, incorporated in many pharmacologically active compounds. Particularly interesting, because of their similarity with compounds 1, are the derivatives substituted at N-4 with carboxymethyl or (aminocarbonyl)methyl groups, which have been shown to be active as selective modulators of ATP-dependent calcium channels, [25][26][27] as inhibitors of aldose reductase, [28] as antagonists of hU-II receptors [29] or as integrin antagonists. [30] The synthetic routes employed in these medicinal chemistry works were definitely longer and less convergent than the two-step protocol described here.…”

Reproducibility and Scalability of Microwave-Assisted Reactions

“…Additionally, the parallel solution phase approach allowed rapid scale-up of selected compounds for further in vivo studies. Caliendo et al described an efficient, facile, and practical parallel combinatorial synthesis of substituted-benzoxazines under microwave irradiation (Caliendo et al, 2004). The procedure involved the use of a specially designed microwave oven for organic synthesis that was suitable for the parallel synthesis of solution libraries.…”