76439-82-2

Upstream product

• 108-24-7 acetic anhydride 
• 76439-79-7 2-cyano-9,9a-dihydro-3,5,7,9a-tetra-t-butylcyclopenta<1,4>benzoxazin-1(3aH)-one 

Relevant academic research and scientific papers

Cyclodienones. Part 6. Preparation of 4-Azido-2,4,6-tri-t-butylcyclohexa-2,5-dienone and its Thermal, Photo-, and Acid-catalyzed Decomposition

Preparation of 4-azido-2,4,6-tri-t-butylcyclohexa-2,5-dienone (3) from 4-bromo-2,4,6-tri-t-butylcyclohexa-2,5-dienone (1) and sodium azide is described.Treatment of (3) with concentrated sulphuric acid afforded 2,6-di-t-butyl-p-benzoquinone (7) in 75percent yield, while the reaction at -10 deg C in chloroform solution gave a tri-t-butylazepinone (5) and 3,5-di-t-butyl-o-benzoquinone (8).Photolysis of (3) in benzene afforded 2,4-di-t-butylcyclopenta-2,4-dienone (11), which was isolated as the dimer (12).Thermolysis of (3) in boiling toluene gave 6-amino-2,4-di-t-butylphenol (17), 2,4,6,8-tetra-t-butyl-1H-phenoxazin-1-one (21), and 2-cyano-9,9a-dihydro-3,5,7,9a-tetra-t-butylcyclopentabenzoxazin-1(3aH)-one (22) in 15, 15 and 48percent yields, respectively.When the thermolysis was carried out with very low reagent concentrations, 5-cyano-2,4-di-t-butylcyclopenta-2,4-dienone (23), in addition to the phenol (17), was obtained.The compound (23) was also obtained by thermolysis of (3) in boiling acetic anhydride and in boiling toluene containing acetic anhydride.The reaction pathway for the formation of compounds (17), (22), and (23) on thermolysis of the azide (3) is also discussed.

CYCLOHEXADIENONES. 3. PREPARATION AND THERMAL DECOMPOSITION OF 4-AZIDO-2,4,6-TRI-t-BUTYL-2,5-CYCLOHEXADIEN-1-ONE

Reaction of 4-bromo-2,4,6-tri-tert-butyl-2,5-cyclohexadien-1-one (1) with sodium azide was carried out in DMF to afford 4-azido-2,4,6,-tri-tert-butyl-2,5-cyclohexadien-1-one (4) in 85percent yield.Thermal decomposition of 4 in boiling toluene gives 6-amino-2,4-di-tert-butylphenol (5), 2,4,6,8-tetra-tert-butylphenoxazin-1-one (7) and 2,4,6,8a-tetra-tert-butyl-7-cyano-8-oxo-5a,8a-dihydrocyclopentenobenzoxazine (8).However, the termal decomposition of 4 was carried out under highly diluted conditions to afford 5 and 2,4-di-tert-butyl-5-cyano-2,4-cyclopentadien-1-one (9)in 48 and 50percent yields, respectively.It was also found that the thermal decomposition of 4 in boiling toluene in the presence of acetic anhydride afforded 6-acetoamido-2,4-di-tert-butylphenol (6) and 9 in 47 and 50percent yields, respectively.The reaction pathways of the formation of 5, 8 and 9 were proposed in the present paper.