78218-02-7

Upstream product

• 87295-45-2 <4-13C>-1-Methylcyclohexen 
• 87295-42-9 <3-13C>Glutarsaeure 
• 87295-41-8 <2-13C>Propan-1,1,3,3-tetracarbonsaeure-tetramethylester 
• 344255-15-8 <3-13C>Glutarsaeure-dimethylester 
• 87295-44-1 <4-13C>-1-Methylcyclohexanol 
• 87295-43-0 <3-13C>-1,5-Dibrompentan 
• 87295-54-3 <3-13C>Pentan-1,5-diol 

Downstream Products

• 87295-46-3 <4-13C>Benzylbromid 
• 87295-49-6 3-(<4-13C>Phenyl)propionsaeure 
• 87295-50-9 1-diazo-4-(<4-13C>phenyl)-2-butanone 
• 87295-48-5 <4-13C>Benzylmalonsaeure 
• 87295-47-4 <4-13C>Benzylmalonsaeure-diethylester 

Relevant academic research and scientific papers

Thermal Azulene Rearrangements. Synthesis and Thermolysis of Azulene

A specific synthesis of azulene (24) is described.The synthetic sequence outlined in scheme 3 begins with the construction of toluene (17) which is performed in 8 steps starting from paraformaldehyde.The suspected scrambling of the label in the dehydrogenation step 16 -> 17 can be suppressed by suitable reaction conditions.After extension of the side chain by 3 carbon atoms to give 1-diazo-4-(phenyl)-2-butanone (21), the labelled azulene is obtained according to Scott's azulene synthesis (21 -> 22 -> 23 -> 24).The vacuum thermolysis of24 (1050 deg C, 10-3 - 10-2 torr) yields naphthalene (25) as the main product (91 percent of the naphthalene formed) in accordance with the norcaradiene-vinylidene mechanism.The remaining 9 percent consist of naphthalene.Besides the formation of naphthalene (15 percent conversion), 24 suffers automerisation to a small extent yielding - and azulene (ca. 3 and 1 percent, respectively).