Synthesis oxadiazines

Arylacetic acids from ar. aldehydes ArGHO ArGH2GOOH via 5-oxazolones and 1,3,5-oxadiazines—Synthesis with addition of 1 G-atom s. 12, 794 ... 

Two Nitrogen Atoms and One Oxygen Atom Synthesis of 1,3,4-oxadiazines 98H(49)557. 

Selective reduction of the 7-oxo group in pyrido[23-synthetic approach to 5,10-dideazatetrahydrofolic acid <00H(53)1207>. Cycloaddition of pyrimido[4,5-c][l,2,5]oxadiazine 96 with 2,3-dihydrofuran affords a new synthesis of dimethyllumazine derivative 97 which undergoes a ring-opening reaction to give pyrazine derivative 98 <00JHC419>. 

Abderrahim etal. <1997SC3039> found that treatment of the ethylidenaminobenzimidazole compound 177 with a Grignard reagent is a convenient tool for the synthesis of the partially saturated benzimidazo[2,3- 7][l,3,5]oxadiazine... 

In contrast to (74), compounds (75) are easily hydrolyzed to amidoximes. IV(4)-Alkylation of oxadiazolones (74) by oxiranes has been used for a synthesis of oxadiazines <75CBi9ll>. 

The addition of hydrazine to diphenylvinylene carbonate 92 quantitatively affords a 1 1 mixture of perhydro-l,3,4-oxadiazin-2-one 93 and 2-oxazolidinone 94 derivatives, both of which are smoothly dehydrated with P2O5 to afford 1,3,4-oxadiazin-2-one 95 and 3-amino-2(3//)-oxazolone 96 (Fig. 5.24), respectively. Addition of primary amines to diphenylvinylene carbonate results in exclusive formation of 3-aIkyl-2(3//)-oxazolones, previously investigated as amino protecting groups in peptide synthesis. 

Pyrazolo[4,3- ][l,3,4]oxadiazine 78, whose preparation is given in Section 10.13.9.1.2(iv), was condensed with various amines to give pyrazolo[3,4- ][l,2,4]triazines 101 (Scheme 78 Table 9) <2002IJB664>. This ring system was earlier reported by synthesis of the fused six-membered ring, through condensation onto pyrazolediones <1996CHEC-II(7)489>. 

A review on the synthesis of 1,3,4-thiadiazines and 1,3,4-oxadiazines shows the formation of the diones 105 and 106 (Equation 57) <1998H(49)557>. TPHA3 was preparedby treatment of 107 with DBU in air (Scheme 10) <1998JA2989,... 

Pyrimido[l,2-a][l,8]naphthyridines synthesis, 2, 599 Pyrimido[5,4-c]oxadiazine purine synthesis from, 5, 591 Pyrimido[4,5-6][ l,4]oxazine synthesis, 3, 312 Pyrimido[2,1 -6]pteridine structure, 3, 284 Pyrimido[5,4-g]pteridine structure, 3, 284 Pyrimidopurines, 5, 566 Pyrimido[4,5-c]pyridazine, aryl- H NMR, 3, 335... 

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