- Synthesis of Pyrimidothiazin-6-one by Retro Diels-Alder Reaction
-
The first mild retrodiene processes resulting in bicyclic heterocycles are described.From norbornene diexo- and diendo-β-amino acids with chloroalkyl isothiocyanates, compounds 3-6 were prepared, which, by retrodiene decomposition, furnished 7 and 8. Keywords: thiazoloquinazolin-5-one; thiazinoquinazolin-6-one; retrodiene decomposition; thiazolopyrimidin-5-one; pyrimidothiazin-6-one.
- Fueloep, Ferenc,Huber, Imre,Szabo, Agnes,Bernath, Gabor,Sohar, Pal
-
-
Read Online
- A facile access to imidazo[2,1-b]thiazole and thiazolo[3,2-a]pyrimidine derivatives
-
A new and efficient method for the synthesis of 2,3-dihydroimidazo [2,1-b]thiazoles 3, 2,3-dihydro-5H-thiazolo[3,2-a]pyrimidin-5-ones 4 and 2,3-dihydro-5H-thiazolo[3,2-a]pyrimidines 5 has been developed. The reactions of N′-(4,5-dihydrothiazol-2-yl)-N,N-dimethylamidines 1 with α-halogenoketones, acid chlorides or acrylic dienophiles were performed, leading to the title products.
- Landreau,Deniaud,Reliquet,Meslin
-
p. 2015 - 2020
(2007/10/03)
-
- FUSED-SKELETON SATURATED SIX-MEMBERED 1,3-N,O, N,N AND N,S HETEROCYCLES, FUSED-SKELETON ARYL-SUBSTITUTED SATURATED ISOINDOLONES
-
In the introduction, a brief survey is given of the main types of fused-skeleton saturated six-membered 1,3-heterocycles serving as model compounds in our earlier investigations and as starting compounds in the present studies.The synthesis and conformational analysis of aryl-substituted fused-skeleton saturated 1,3-oxazines and of aryl-substituted hetero-condensed saturated isoindolones are treated. cis-trans isomerization in the saturated isoindolone moiety of the resulting tricyclic, tetracyclic and pentacyclic systems is discussed in connection with the ring-closure reactions of cis- and trans-1,2-disubstituted 1,2- and 1,3-difunctional alicyclic compounds to give alicycle-fused six-membered 1,3-heterocycles.The cycloaddition reactions of dihydro-1,3 and 3,1-oxazines and the conformations of the alicycle-fused tetrahydrooxazine-azetidinone derivatives obtained are presented.Methods are given for the preparation of saturated thiazolo- and thiazinoquinazolinones.Unambiguous, mainly one-pot syntheses for the preparation of 1,3-heterocycles by a retro Diels-Alder method are discussed.
- Bernath, G.
-
p. 509 - 530
(2007/10/02)
-