2 Ethoxy 3,4-dihydro

Tribenzylphosphanoxid (Schmp. 211-214°) entsteht zu 16%, wenn man die fur Phos-phin- und Phosphonsaureester bewahrte Methode der reduktiven Alkylierung mit Na-trium-bis-[2-mcthoxy-ethoxy]-dihydro-aluminat auf das System Phosphorsaure-triethyl-ester, Benzylchlorid anwendet (s. S. 33)233. 

Natrium-bis-[2-methoxy-ethoxy]-dihydro-aluminat144 reduziert Carbonsau-re-ester zu Aldehyden in guter bis ausgezeichneter Ausbeute, ohne daB der Aldehyd als Aluminat-Komplex gebunden wird. Das bei dieser Reaktion als zweites Produkt entste-hende komplexe Alkanolat besitzt auch bei tiefen Temperaturen (< 50°) eine gute Los-lichkeit. 

Wird dem Natrium-bis-[2-methoxy-ethoxy]-dihydro-aluminat ein Aquivalent wasserfrei-es Ethanol zugesetzt, so lassen sich unter milden Bedingungen (0°, 1 Stde.) Lactone in Lac-tole in guten Ausbeuten uberfuhren, die mit anderen Reduktionsmitteln nur in geringer Ausbeute erhalten werden145 z.B. ... 

Eine weitere Modifizierung besteht durch die Zugabe eines Aquivalents 1-Methyl-pipera-zin zum Natrium-bis-[2-methoxy-ethoxy]-dihydro-aluminat. 

Antioxidants. The 1,2-dihydroquinolines have been used in a variety of ways as antioxidants (qv). For example, l,2-dihydro-2,2,4-trimethylquinoline along with its 6-decyl [81045-48-9] and 6-ethoxy [91-53-2] derivatives have been used as antio2onants (qv) and stabilizers (68). A polymer [26780-96-1] of l,2-dihydro-2,2,4-trimethylquinoline is used in resins, copolymers, lubricant oils, and synthetic fibers (69). These same compounds react with aldehydes and the products are useful as food antioxidants (70). A cross-linked polyethylene prepared with peroxides and other monomers in the presence of l,2-dihydro-6-ethoxyquinoline produces polymers with a chemically bonded antioxidant (71). 

The principal objection to -PDA antiozonants is their staining characteristics. The lack of suitable alternative antiozonants for light-colored diene mbber articles is one of the outstanding problems in mbber technology. Pew chemical antiozonants outside the class of -PDAs have much commercial importance. One of the few exceptions to this rule is 6-ethoxy-l,2-dihydro-2,2,4-trimethylquinoline [91-53-2] one of the first commercial antiozonants. 

Thiazolo[3,2-c]pyrimidinium, anhydro-8-ethoxy-2,3-dihydro-5-methyl- H NMR, 6, 676 (69ACS2437) 5H-Thiazolo[3,2-a]pyrimidin-5-one IR, 6. 681 (71JCS(C)2094)... 

Benzo[b]furan, 2,3-dihydro-2-phenyl-synthesis, 4, 697 Benzo[b]furan, 2,3-dihydroxy-tautomerism, 4, 37 Benzo[6]furan, 4,6-dimethoxy-acylation, 4, 606 Benzo[6]furan, 2,3-dimethyl-acetylation, 4, 606 bromination, 4, 605 photooxygenation, 4, 642 Benzo[b]furan, 5,6-dimethyl-2,3-diphenyl-applications, 4, 709 Benzo[b]furan, 1,3-diphenyl-vertical ionization potential, 4, 587 Benzo[b]furan, 2-ethoxy-5-hydroxy-synthesis, 4, 127... 

Pteridinium bromide, 2-amino-4-ethoxy-3,4-dihydro-X-ray analysis, 3, 267 Pteridin-2-one, 4-amino-, 3, 273 hydrolysis, 3, 294 methylation, 3, 297 structure, 3, 273... 

H-Pyran, 4-alkyl-5,6-dihydro-conformation, 3, 630 2H-Pyran, 5-alkyl-2-ethoxy-3,4-dihydro-reactions... 

Pyran-3-one, 2-alkoxytetrahydro-conformation, 3, 631 Pyran-3-one, 6-ethoxy-3,6-dihydro-2-substituted,... 

Another approach to the l-oxo-l,2-dihydro-j8-carboline system is that due to King and Stiller. When 2-ethoxy carbonyl-3-formyl-indole is condensed with hippuric acid the azlactone 162 is formed, which, with 10% methanolic potassium hydroxide, gives a mixture of the orthoester 163 and the potassium salt 164. 

Step 2 5-(p-Chlorophenyll-5-Hydroxy-2,3-Dihydro-5H-lmidazo[2,1 -a]Isoindole 1-(p-Chlorophenyl)-3-ethoxy-1 H-isoindole (1 g), 2 g of ethyleneimine hydrotetrafluoroborate moistened with methylene chloride (containing approximately 0.66 g of dry salt) is refluxed in 25 ml of absolute toluene for 2 hours in an atmosphere of nitrogen. The result-... 

Dimethyl 4-ethoxy-2,7-dimethyl-4,5-dihydro-l 7/-azepine-3,6-dicarboxylate (1) with sodium ethoxide in refluxing diethyl ether, or on standing at room temperature in carbon tetrachloride solution, readily loses ethanol to yield dimethyl 2,7-dimethyl-4//-azepine-3,6-dicar-boxylate (2).29 The 4-methoxy derivative is also unstable and on warming at 100 C under reduced pressure loses methanol to yield the same product (44%).120... 

Ethyl 6,7-diaryl-3-hydroxy-2-oxo-2,5-dihydro-l//-azepine-4-carboxylates, e.g. 20, with diazomethane methylate solely at the 3-hydroxy group, whereas with Meerwein s reagent the 7-ethoxy-4/7-azepines, e.g. 21, are formed.48... 

Bromo-6-ethoxy-7//-dibenz[/>,d]azepin-7-one(28, R1 = OEt Rz = Br). prepared by oxidation of the 5,6-dihydro derivative 27 with manganese(IV) oxide, is one of the few examples of unsaturated dibenz[/>,d]azepines to be reported.4 Earlier reports concerning the preparation of the parent system 28 (R = R2 = H) are incorrect the product is in fact a dimer.115... 

Amino-77/-dibenz[/),t/]azepin-7-ones, e.g. 7, prepared either by successive bromination, aminodebromination, and dehydrogenation of 5-tosyl-5A/-dihydro 7>,t/]azepin-7(6//)-ones, or by the oxidation of 6-ethoxy-6,7-dihydro-5//-dibenz 7>,r/]azepincs with lead(IV) acetate followed by aminodemethoxylation, on treatment with a bidentate nucleophile (e.g.. benzene-1,2-diamine or 2-aminobenzenethiol) yield the pentacyclic systems 8 and 9, respectively.27... 

The pyrrolotriazines 32 were prepared from 3,4-dihydro-5-ethoxy-2//-pyrrole 31 by sequential reaction with hydrazine hydrate and a-oxoesters (85GEP3340026). They are useful as selective herbicides (Scheme 10). 

S.P. solid-phase technique L.P. liquid-phase technique OPTcp pentachlorophenyl ester TEEP tetraethyl pyrophosphit OTCp trichlorophenyl ester ONp p-nitrophenyl ester ONSu N-hydroxysuccinimido ester OPFp pentafluorophenyl ester OQu 8-hydroxyquinyl ester OPy 3-hydroxy-pyridyl ester ODnp 2,4-dinitrophenyl ester DCC dicyclohexylcarbodiimide HOBn 3-hydroxy-4-oxo-3,4-dihydro-l,2,3-benzotriazin Opi JV-hy-droxypiperidine EEDQ 2-ethoxy-l-ethoxycarbonyl-l,2-dihydroquinoline Tos p-toluenesulfonyl PTC propanetricarboxylic acid OBu tm-butyl ester Nva norvaline Aha aminohexanoic acid Om ornithine... 

Isonitriles react with alkenylcarbene complexes to form initially at 0 °C a 3-ethoxy-3-styrylketeneimine complex, which on warming to room temperature leads to the formation of a cyclic 3-ethoxy-2,5-dihydro-2-pyrrolylidene complex. Finally, on heating to 100 °C a pyrrole derivative is produced [80] (Scheme 33). 

CN 2-amino-l,9-dihydro-9-[[2-hydroxy-l-(hydroxymethyl)ethoxy]methyl]-6//-purin-6-one monosodium salt... 

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