Compounds with a (2
H)-1,4-benzoxazin-3(4
H)-one skeleton have attracted the attention of phytochemistry researchers since 2,4-dihydroxy-(2
H)-1,4-benzoxazin-3(4
H)-one (DIBOA) and 2,4-dihydroxy-7-methoxy-(2
H)-1,4-benzoxazin-3(4
H)-one (DIMBOA) were isolated from plants belonging to thePoaceae family. These compounds exhibit interesting biological properties, such as phytotoxic,antimicrobial, antifeedant, antifungal, and insecticidal properties. These chemicals, in addition to awide variety of related compounds involved in their metabolism, detoxification mechanisms, anddegradation on crop soils and other systems, have high interest and in some cases potential agronomicutility. This paper presents a complete review of the methods employed for their synthetic obtentionin addition to some of the authors' own contributions to their chemistry. The degradation andphytotoxicity experiments carried out in ongoing research into the potential agronomic utility of thesecompounds required large amounts of them, which were obtained from natural sources. This paperpresents a modified methodology to access DIMBOA from
Zea mays cv. Apache and to obtain 2-
O-
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-
D-glucopyranosyl-2,4-dihydroxy-(2
H)-1,4-benzoxazin-3(4
H)-one (DIBOA-Glc) and DIBOA from
Secale cereale L. New synthetic methodologies were employed for the obtention of the lactams2-hydroxy-(2
H)-1,4-benzoxazin-3(4
H)-one and 2-hydroxy-7-methoxy-(2
H)-1,4-benzoxazin-3(4
H)-oneand the malonamic acids
N-(2-hydroxyphenyl)malonamic acid and
N-(2-hydroxy-7-methoxyphenyl)malonamic acid. The aminophenoxazines 2-amino-7-methoxyphenoxazin-3-one and 2-acetamido-7-methoxyphenoxazin-3-one have been synthesized in the authors' laboratory by novel procedures.All of the methodologies employed allowed the desired compounds to be obtained in high yield andin an easy-to-scale manner.Keywords: Allelochemicals; DIMBOA; DIBOA; soil degradation products; wheat; isolation; synthesis;preparation