Triethoxy

To a mixture of 0.20 mol of 1,1,4-triethoxy-2-butyne [see Chapter III, Exp. 40), 60 ml of dry THF and 50 ml of dry diethyl ether was added at -45 to -50°C a solution of 0.42 mol of ethyllithium in about 280 ml of diethyl ether (see Chapter II, Exp. 1). Stirring at -5o°C was continued for 30 min, then the reaction mixture was poured into 300 ml of saturated ammonium chloride solution. After shaking, the layers were separated and the aqueous layer was extracted twice with small portions of diethyl ether. The combined ethereal solutions were dried over magnesium sulfate and concentrated in a water-pump vacuum and the residue wasdistilled at about... 

CN 7-amino-4,5,6-triethoxy-3-(5,6,7,8-tetrahydro-4-methoxy-6-methyl-l,3-dioxoIo[4,5-g]isoquinolin-5-yl)-1 (3//)-isobenzofuranone... 

A kinetic study of the previously reported substitution of aromatic nitro groups by tervalent phosphorus has established an aromatic 5n2 mechanism. Similarities in values of activation energies, and in relative reactivities of phosphite and phosphonite esters, between this displacement and the Arbusov reaction suggest a related mechanism (31), while the lack of reactivity of p-dinitrobenzene is attributed to the need for intramolecular solvation (32). The exclusive formation of ethyl nitrite, rather than other isomers, is confirmed from the decomposition of triethoxy-(ethyl)phosphonium fluoroborate (33) in the presence of silver nitrite. A mechanism involving quinquevalent phosphorus (34) still seems applicable, particularly in view of the recent mechanistic work on the Arbusov reaction. ... 

The silane coupling agents which are frequently used are bis-(3-triethoxysilylpropyl)tetrasulphane and 3-thio-cyanatopropyl triethoxy silane. 

It is clear that the ionizing power of the solvent used is important in many of these reductions. When 2,4,6-trimethylbenzyl chloride is heated with diphenylsi-lane in nitrobenzene at temperatures as high as 130°, no isodurene is formed.193 Not unexpectedly, the same lack of reactivity is reported for a series of benzyl fluorides, chlorides, and bromides substituted in the para position with nitro or methyl groups or hydrogen when they are heated in nitrobenzene solutions with triethylsilane, triethoxy silane, or diphenylsilane.193... 

Unpublished work from our laboratory l2b) indicated that triethoxy-silane behaved differently than trichlorosilane. With linear olefins and chloroplatinic acid in a ratio of 1 5 x 10 3 it added much more slowly, did not isomerize the olefin, and formed secondary alkyltriethoxysilanes. However, it added rapidly to allyl acetate (see Table IV). 

The hydrosilation of butadiene, isoprene and other simple conjugated dienes with platinum catalysts has not been intensively studied. It usually occurs by 1,4 addition and only at elevated temperatures (10). Although palladium catalysts are practically ineffective to hydrosilate an alkene, they are very active under mild conditions with conjugated dienes to give two principal products, sometimes in 100% yields. With triethoxy silane, butadiene, and PdCl2(PhC=N)2 (5.5 x 103 moles/mole) at 22°C for 24... 

Preparation of 2,2,2-triethoxy-2,2-dihydro-5-methyl-l,2A,5-oxaphospholene —Preparation of an oxyphosphorane... 

The Sonogashira reaction of 5-bromopyrimidine with ]V,lV-dimethylpropargylamine gave aminoalkyne 81 [59], whereas the union of 6-methyl-2-phenyl-4-iodopyrimidine and 3,3,3-triethoxy- 1-propyne afforded ester 82 after acidic hydrolysis [60]. 

Aromatic nitriles were converted to aldehydes in 50-95% yields on treatment with 1.3-1.7mol of sodium triethoxy aluminum hydride in tetrahydrofuran at 20-65° for 0.5-3.5 hours [1149. More universal reducing agents are lithium trialkoxyaluminum hydrides, which are applicable also to aliphatic nitriles. They are generated in situ from lithium aluminum hydride and an excess of ethyl acetate or butanol, respectively, are used in equimolar quantities in ethereal solutions at —10 to 12°, and produce aldehydes in isolated ytelds ranging from 55% to 84% [1150]. Reduction of nitriles was also accomplished with diisobutylalane but in a very low yield [7/5/]. 

Triethyl orthoacetate Orthoacetic acid, triethyl ester (8) Ethane, 1,1,1-triethoxy- (9) (78-39-7)... 

---