Easy synthesis of 2,4-dialkyl substituted phenols and anisoles from p-bensoquinone
摘要:
The reaction of p-benzoquinone (1) with several organolithium compounds (methyl-, ethyl-, n-butyl, phenyllithium) leads directly, after acid hydrolysis, to the corresponding 2,4-dialkylphenols 4a-d, resulting from a rearrangement/aromatization process of the corresponding intermediate diols 3. The use of two different alkyllithium reagents leads to the mixed products 4e.f. Alternatively, the same results are obtained treating the crude isolated diols 3 with a catalytic amount of concentrated sulfuric acid. Applying this last methodology to the diethers 2, 2,4-dialkylanisoles 8 are obtained. A possible mechanism is proposed.
Method for the preparation of aromatic chloroformates
申请人:Davis Charles Gary
公开号:US20060293535A1
公开(公告)日:2006-12-28
A method for preparing an aromatic chloroformate comprising, introducing a mixture of at least one aromatic hydroxyl compound, phosgene, at least one solvent, and at least one organic base into a flow reactor to obtain a unidirectionally flowing reaction mixture. The unidirectionally flowing reaction mixture is maintained at a temperature between about 0° C. and about 60° C. to produce a single product stream comprising an aromatic chloroformate.
Mechanisms of the Photochemical Rearrangement of Diphenyl Ethers
作者:Naoki Haga、Hiroaki Takayanagi
DOI:10.1021/jo9517196
日期:1996.1.1
The mechanism of the photochemical rearrangement of diphenyl ether (1a) was studied. Irradiation of 1a in ethanol gave 2-phenylphenol (2, 42%) and 4-phenylphenol (3, 11%) as rearrangement products, in addition to phenol (4, 30%) and benzene (5, 25%) as diffusion products. Cross-coupling experiments employing [(2)H(10)]1a demonstrated that the formation of 2- and 4-phenylphenol was an intramolecular
Reaction of p-substituted phenols 2 with a catalytic amount of 4-iodophenoxyacetic acid (1) and Oxone® as a co-oxidant in tetrahydrofuran (THF) or 1,4-dioxane–water gave the corresponding p-quinols 3 in excellent yields. Reaction of p-dialkoxyarenes 4 in 2,2,2-trifluoroethanol–water gave the corresponding p-quinones 5 in excellent yield without purification. These reactions provide efficient and practical
Efficient Synthesis of p-Quinols Using Catalytic Hypervalent Iodine Oxidation of 4-Arylphenols with 4-Iodophenoxyacetic Acid and Oxone
作者:Takayuki Yakura、Masanori Omoto
DOI:10.1248/cpb.57.643
日期:——
Efficient synthesis of p-quinols (2) usingcatalytic hypervalent iodine oxidation of 4-arylphenols (1) with 4-iodophenoxyacetic acid (3) and Oxone was developed. Reaction of 1 with a catalytic amount of 3 in the presence of Oxone as a co-oxidant in tetrahydrofuran or 1,4-dioxane-water gave the corresponding 2 in excellent yields.
Silylated polycarbonate polymers, method of making, and articles
申请人:Lens Jan Pleun
公开号:US20080306294A1
公开(公告)日:2008-12-11
A silylated dihydroxy aromatic compound of the formula (1a);
wherein G
a
and G
b
are each independently C
1-12
alkyl, —OSi(C
1-12
alkyl)
3
, C
1-12
arylalkyl, or —OSi(C
1-12
arylalkyl)
3
; Z
a
and Z
b
are each independently a straight or branched C
2-18
alkylene, a C
8-18
arylalkylene, or a C
8-18
alkylarylene, X
a
is a direct bond, a heteroatom-containing group, or a C
1-18
organic group, and r and s are each independently 1 or 2 is disclosed.