Some common heterocyclic compound, 1073-39-8, name is 3-Bromobicyclo[4.2.0]octa-1,3,5-triene, molecular formula is C8H7Br, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. COA of Formula: C8H7Br
The synthesis of a tetracene brominated in the 2-position is shown by way of example in the following illustration: In a first step, alpha-chloro-o-xylene 1 was subjected to pyrolysis at approximately 800 C. and 0.5 mbar. Benzocyclobutene 2 was obtained in a 45% yield. The selective bromination thereof was carried out by treating benzocyclobutene, dissolved in acetic acid, with a mixture of bromine and iodine at room temperature, resulting in 4-bromobenzocyclobutene 3. Dissolving in toluene and heating with a slight molar excess of 1,4-dihydro-1,4-epoxynaphthalene 4 at 220 C. for 20 hours resulted in an 80% yield of a pure endo/exo mixture of the Diels-Alder addition product 5, a colorless crystalline material. This material was heated at reflux in acetic anhydride in the presence of concentrated hydrochloric acid, thus forming 9-bromo-6,11-dihydrotetracene 6. The Yamamoto coupling then resulted in 2-(5,12-dihydrotetracene-2-yl)-5,12-dihydrotetracene 7. The coupling reaction was carried out in an approximately 80% yield in a mixture of dimethylformamide and toluene at 80 C., using bis(cyclooctadienyl) nickel(0) in stoichiometric quantities. After recrystallization from o-dichlorobenzene, compound 7 was dehydrogenated by treatment with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in boiling o-xylene. After purification by repeated vacuum sublimation, orange-red crystals of 2-(tetracene-2-yl) tetracene 8 were obtained in a yield of 75%. All intermediate products were characterized by 1H and 13C NMR spectroscopy and mass spectroscopy. Compound 8 was characterized by UV-visible spectroscopy.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1073-39-8, its application will become more common.
Reference:
Patent; Rehahn, Matthias; Roth, Michael; Von Seggern, Heinz; Schmechel, Roland; Ahles, Marcus; US2008/214838; (2008); A1;,
Bromide – Wikipedia,
bromide – Wiktionary