Tetrahydro-2H-l,4-oxazine

TETRAHYDRO-2H-l,4-OXAZINE (110-91-8) Forms explosive mixture with air (flash point 98°F/37°C). A strong organic base. Violent reaction with acids, strong oxidizers, cellulose nitrate, nitromethane. Incompatible with organic anhydrides, isocyanates, vinyl acetate, acrylates, substituted allyls, alkylene oxides, epichlorohydrin, ketones, aldehydes, alcohols, glycols, phenols, cresols, caprolactam solution, nitrocompounds, perchlorates. Attacks aluminum, copper, lead, tin, zinc, and their alloys, and some plastics, rubber, and coatings. 

Tergitol 3-A-B Nonionic Ethoxylated Tridecanol Tetrahydro-2H-l, 4-Oxazine Morpholine... 

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... 

The compounds from the classes of the methylene-bisoxazolidines (e.g 3,3 -methylenebis[5-methyloxazolidine] (II, 3.3.9.)CAS N° 66204-44-2), methylene-bis-oxazines (e.g. 3,3 -methylenebis-[tetrahydro-2H-l,3-oxazine] (II, 3.3.16.) CAS N° 63489-63-4) or aminals (e.g. N,N -methylene-bis-morpholine (11,3.3.22.) CAS N° 5625-90-1) display better properties with regard to effectiveness against moulds, rapid microbicidal effectiveness, and temperature stability. Further advantages of these compounds are their solubility behaviour, as a result of which they can be used in anhydrous as well as water containing systems. Their aqueous dilutions are not as alkaline as e.g. those of the hexahydrotriazines, and are therefore less aggressive to the skin. The N,N -methylene-bis-morpholine cannot be used in Germany. The TRGS 611 prohibits secondary amines and compounds which can release secondary amines. 

De Wald HA, Heffner TG, Jaen JC, Lustgarten DM, McPhail AT, Meltzer LT, Pugsley TA, Wise LD (1990) Synthesis and dopamine agonist properties of ( )-trans-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[l]benzo-pyrano [4,3-b]-l,4-oxazin-9-ol and its enantiomers. J Med Chem 33 445 150. 

Dijkstra D, Mulder TB, Rollema H, Tepper PG, van der Weide J, Horn AS (1988) Synthesis and pharmacology of trans-4-n-propyl-3,4,4a,10b-tetrahydro-2H,5H-l-benzopyrano[4,3-b]-l,4-oxazin-7- and -9-ols the significance of nitrogen pKa values for central dopamine receptor activation. J Med Chem 37 2178-2182. 

H-Purin l,9-Diraethyl-2,6-dioxo-8-phenyl-l,2,3,6-tetrahydro- E9b/2, 356 [5-NO —1-R —2,6-dioxo—4-NHR — pyrimdin/Ar — CHO] 2H-[Pg.1124]

H-l,2-Oxazine, 3,6-dihydro-6-(2-pyridyl)-mass spectra, 2, 529 2H-l,2-Oxazine, tetrahydro-synthesis, 2, 92 4 H-1,2-Oxazine, 5,6-dihydro-pyrolysis, 3, 999 synthesis, 3, 1017 tautomerism, 3, 999 4H-l,2-Oxazine, 5,6-dihydro-3-methyl-metallation, 1, 484 4H-1,2-Oxazine, 5,6-dihydro-3-nitro-reactions, 3, 1000 6H-l,2-Oxazine, 3,5-diphenyl-stability, 3, 997 synthesis, 3, 1014... 

Bei Verwendung eines groBen Oberschusses von Lithiumalanat wird 2,4-Dioxo-3,3- dibutyl-3,4,7,8- tetrahydro-2H,6H- (pyrimido-[2,l-b]-l,3-oxazin) mit einem diacylierten Isoharnstoff-Gertist in 5,5-Bis-[hydroxymethyl]-nonan (66% d.Th.) und 2-Oxo-hexahy-... 

Fluor-phenylimino)-tetrahydro-l,3-oxazin bzw. -1,3-thiazin reagieren mit einem Uber-schuB an Butyllithium bei — 75° unter intermediarer Arin-Bildung zu 3,4-Dihydro-2H-(Jpenz-imidazo[2,l-b]-l,3-oxazin (X = O 90% Schmp. 115-118°) bzw. -2H-(benzimidazo[2,l-b]-1,3-thiazin> (X = S 62% Schmp. 181-183° s.a. S. 246)122 ... 

The low temperature H-NMR spectra of 2-methyl-3,6-dihydro-2H-1,2-oxazine (239) gives a AG° favoring the /V-Meeq of 0.9 kcal mol", which is significantly less than that for the tetrahydro-l,2-oxazine (>1.9 kcal mol"1).246 This is similar to the decrease in conformational free energy of a methyl substituent on going from methylcyclohexane (1.7 kcal mol"1) to 4-methylcyclohexene (1.0 kcal mol 1),247 and the equilibrium 240 241 may represent a balance between lone-pair-Ti-bond repulsion in 240 and lone-pair-lone-pair repulsions in 241.246... 

Tetrahydro-2H-6H-pyrimido[2,l-b]-l,3-oxazine-2,4-diones from tetr ahy dro-1 -malonyl-2 (IH) -pyrimidinones... 

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