Process for preparing hydroxyalkylbenzocyclobutenes
申请人:The Dow Chemical Company
公开号:US05349095A1
公开(公告)日:1994-09-20
A process for preparing a substituted or unsubstituted 3- or 4-hydroxyalkylbenzocyclobutene compound comprises reducing a corresponding 3- or 4-formyl or ketobenzocyclobutene compound with a hydride at a temperature below that at which dimerization or oligomerization of the formyl- or ketobenzocycloutene compound or the thus-produced hydroxyalkylbenzocyclobutene compound is a significant side reaction, for a time sufficient to convert the formyl- or ketobenzocyclobutene compound to the hydroxyalkylbenzocyclobutene compound. In a two-step process, formylbenzocyclobutenes are prepared from bromobenzocyclobutenes in 90% yield or from benzocyclobutenes in a 70% yield, and then converted to hydroxymethylbenzocyclobutenes for an overall yield of about 85% from a bromobenzocyclobutene or of about 65% from a benzocyclobutene. In a two-step process, ketobenzocyclobutenes from bromobenzocyclobutene Grignard reagents and an N-alkanoyl- or N-aroyl-2-methylaziridine are converted to hydroxyalkylbenzocyclobutenes in high yields.
C8H6 Thermal Chemistry. 7-Methylenecyclohepta-1,3,5-dienyne (Heptafulvyne) by Flash Vacuum Thermolysis–Matrix Isolation. Chemical Activation in the Rearrangements of Phenylenedicarbenes and of Benzocyclobutadiene to Phenylacetylene
compound 2 as observed by IR spectroscopy and on-line mass spectrometry. FVT of 8 at 600–800°C causes rearrangement of 11 to phenylacetylene 12 and benzocyclobutadiene 13. Mechanisms for the rearrangements are proposed. Facile rearrangement of benzocyclobutadiene to phenylacetylene is ascribed to chemical activation, which is also seen to be involved in the rearrangement of p-, m-, and o-phenylenebiscarbenes
Observation of benzocyclobutadiene by flow nuclear magnetic resonance
作者:Walter S. Trahanovsky、D. R. Fischer
DOI:10.1021/ja00168a059
日期:1990.6
Benzocyclobutadiene (1) is a key molecule in the understanding of the aromaticity and antiaromaticity of cyclic delocalized pi}-electron systems. The high reactivity of 1 has made it difficult to study, but it has been isolated in an Ar matrix at 20 K, and its IR, UV-visible, and photoelectron spectra have been obtained. In this communication we report the sup 1}H NMR spectrum of 1 obtained by the
苯并环丁二烯 (1) 是理解环状离域 pi} 电子系统的芳香性和反芳香性的关键分子。1 的高反应性使其难以研究,但它已在 20 K 的 Ar 基质中分离,并已获得其红外、紫外-可见光和光电子光谱。在本次通讯中,我们报告了通过流动核磁共振技术获得的 1 的 sup 1}H NMR 谱。
Process for preparing 3-chloromethylbenzo-cyclobutene
申请人:The Dow Chemical Company
公开号:US05099083A1
公开(公告)日:1992-03-24
3-chloromethylbenzocyclobutene is prepared by reacting benzocyclobutene with chloromethyl methyl ether in the presence of stannic chloride at a temperature of about -120.degree. C. to about -40.degree. C. and neutralizing the resulting reaction mixture comprising 3-chloromethylbenzocyclobutene at a temperature of about -80.degree. C. to about -70.degree. C.