Mild and efficient oxidative aromatization of 4‐substituted‐1,4‐dihydropyrimidines using (diacetoxyiodo)benzene

Abstract

magnified image 4‐Alkyl or aryl‐1,4‐dihydropyrimidines were readily oxidized by (diacetoxyiodo)benzene under mild reaction conditions to the corresponding pyrimidine derivatives in good to excellent yields. J. Heterocyclic Chem., (2010).

Oxidative Dehydrosulfurative Carbon–Oxygen Cross-Coupling of 3,4-Dihydropyrimidine-2-thiones with Aryl Alcohols

“…When 2-mercaptopyrimidine 6 was reacted with phenol, the corresponding ether 7 was obtained in 56% yield (eq 2), which is in line with the proposition that tautomerization of the DHPM yielding the corresponding thiol is involved in the reaction. We found that pyrimidinyl thioether 8 was also compatible with the reaction method (eq 3), and the reaction of dihydropyrimidinyl thioether 9 proceeded via oxidative dehydrogenation to yield 8 as an intermediate, prior to the C–O coupling (eq 4). On the basis of these results, it is likely that the reaction proceeds via tautomerization and oxidative dehydrogenation, followed by C–O coupling.…”

Oxidative Aromatization of 3,4-Dihydroquinolin-2(1H)-ones to Quinolin-2(1H)-ones Using Transition-Metal-Activated Persulfate Salts

“…With respect to the preparation of quinolin-2­(1 H )-one derivatives, one widely used strategy is the oxidative aromatization of their corresponding 3,4-dihydroquinolin-2­(1 H )-one derivatives. Although a number of methods for the oxidative aromatization of heterocyclic compounds have been developed, − they are rarely reported for the oxidative aromatization of 3,4-dihydroquinolin-2­(1 H )-one derivatives except using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). − …”

Copper-promoted dehydrosulfurative carbon–nitrogen cross-coupling with concomitant aromatization for synthesis of 2-aminopyrimidines

“…Pyrimidinyl thioether 1t (ref. 32) and dihydropyrimidinyl thioether 1u , 4 b which provide the same product 3a , were also compatible with the reaction method (Scheme 4c and d). We found that the reaction of 1u proceeded via aromatization to yield pyrimidine 1t as an intermediate in advance of C–N coupling.…”