2-(Tributylstannyl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-indole: Synthesis and use as a 1H-indol-2-yl-anion equivalent
作者:Giovanni Palmisano、Marco Santagostino
DOI:10.1002/hlca.19930760622
日期:1993.9.22
Pd-Catalyzed reaction of 2-(tributylstannyl)-1-[2-(trimethylsilyl)ethoxy]methyl}-1H-indole (5) with a variety of aryl, heteroaryl, vinyl, and allyl halides provides an efficient entry to the corresponding cross-coupled products (see Table).
3-Chloro- and 3-bromo-4-methoxycoumarins 1a,b were readily transformed into 4-halo-5-(2-hydroxyphenyl)-3-oxo-2,3-dihydropyrazoles 2a,b with hydrazines. In the reaction of 1a,b with excess hydrazine and phenylhydrazine in boiling ethanol, unexpected 4-hydrazono-3-(2-hydroxyphenyl)-2-pyrazolin-5-ones 3, 5 were obtained. The structure of 3 was determined by X-ray diffraction analysis.
Synthesis and some reactions of 6-(2-hydroxyphenyl)-2-thiouracils.
作者:HIKARI MORITA、MASAAKI TANAKA、KANAME TAKAGI
DOI:10.1248/cpb.31.3728
日期:——
6-(2-Hydroxyphenyl)-2-thiouracil (2a) and its 5-chloro and 5-bromo derivatives (2b, c) were synthesized by the reactions of 4-methoxycoumarin (1a) and 3-chloro- and 3-bromo-4-methoxycoumarins (1b, c), respectively, with thiourea in the presence of sodium ethoxide. In these reactions, compound 1c gave not only the pyrimidine 2c, but also the Perkin rearrangement product : N-(3-ethoxybenzofuran-2-carbonyl)thiourea (3). 2-Thiouracils 2a-c were converted to the uracil derivatives (6a, b). Reactions of 2a-c with some cyclic amines and the methylation of 2b, c with methyl iodide were also examined.