Oxazine, Tetrahydro

Chemical Name 2-(3-Trifluoromathyl)phenyl-4-isopropyl-tetrahydro-1,4-oxazine Common Name —... 

Motpholines are a chemical class of organic compounds with the six-membered ring tetrahydro-1,4-oxazine, as their basic structure. 

Tetrahydrobenzene, see Cyclohexene Tetrahydro-o-cresol, see o-Methylcyclohexanone Tetrahydro-1,4-dioxin, see 1,4-Dioxane Tetrahydro-p-dioxin, see 1,4-Dioxane Tetrahydro-1,4-isoxazine, see Morpholine Tetrahydro-1,4-oxazine, see Morpholine Tetrahydro-p-isoxazine, see Morpholine Tetrahydro-2//-l,4-oxazine, see Morpholine... 

Tetrahydro-1,4-oxazines are better known, and spectra for morpholine and its A -methyl derivative were published as early as 1964 <1964JCS4269>, so only a few examples of data for fused ring and oxo derivatives are collected here. The chemical shifts for the NH protons are shown for compounds 73-75, 78, and 79. 

Figure 7 Cycloalkane-fused tetrahydro-1,4-oxazin-3-ones.

Case Study of Tetrahydro-1,4-Oxazine (Morpholine). As in the case of aromatic pollutants, the oxidation of the N atom and the C atoms was observed with or without the destruction of the morpholine cycle (92). Also, the abstraction of H atoms to form methyl groups was illustrated by the formation of A-hydroxyamino-2-ethenyl ethyl ether, /V-formyl-formamine, and acetate ions. When the starting morpholine concentration was increased, intermediate products with mass peaks much greater than the molecular mass of morpholine were detected, showing that coupling reactions occurred the concentrations of these intermediates were very low. 

Tetrahydro-1,4-oxazines are normally prepared by the cyclization of diethanolamines in the presence of acids, although an alternative route employs the reaction of diQS-chloroethyl) ethers with ammonia or amines (Scheme 124) (12JCS1788). Similar procedures can be adapted to the syntheses of tetrahydro-1,4-thiazines, their 1-oxides and 1,1-dioxides (25JA282). 

Disubstituted tetrahydro-1,4-oxazines are also obtained from the reaction of the ethanolamines (282) and oxiranes in the presence of 70% sulfuric acid. The protective AT-benzyl substituent can be easily removed by hydrogenolysis over palladium on carbon (Scheme 125) (80T409). 2-Oxo derivatives are available if ethanolamines are replaced by a-amino acids, or if ethanolamines are reacted with a-bromoacetates (Scheme 126) <79CR(C)(288)229>. 

SYNS DIETHYLENE IMIDE OXIDE DIETHYLENE IMIDOXIDE DIETHYLENE OXIMIDE DIETHYL-ENTMIDE OXIDE MORPHOLINE, AQUEOUS MIXTURE. pOT) 1-OXA-4-AZACYCLOHEXANE TETRAHYDRO-p-ISOXAZINE TETRAHYDRO-1,4-ISOXAZINE TETRAHYDRO-1.4-OXAZINE TETR. HYDRO-2H-l, 4-OXAZINE... 

As with tetrahydro-1,3-oxazines the tetrahydro-1,4-oxazine ring system is stable to reduction by complex metal hydrides, and, for example, LAH can be used to reduce the lactam carbonyl function of mor-... 

Oxazines are six-membered-ring analogs of piperazine where the nitrogen atom in position 4 is replaced by an oxygen atom. The oxazines in tobacco and tobacco smoke are morpholine and several morpholine derivatives. The most discussed morpholine recently is Af-nitrosomorpholine (NMOR). This volatile A-nitrosamine (NMOR) has been identified in both tobacco and tobacco smoke. Morpholine is an organic heterocycle that features both amine and ether functional groups. Morpholine is also called tetrahydro-1,4-oxazine. Figure XVII.D-1 illustrates the parent structures of the oxazoles and oxazines identified in tobacco and tobacco smoke. 

Synonyms/Trade Names Diethylene imidoxide Diethylene oximide Tetrahydro-1,4-oxazine Tetrahydro-p-oxazine ... 

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