Ethyl isocyanate Ethanol

Triethylamine (3.0 g, 30 mmol) is added dropwise during 30 min to a solution of a-amino-a-phenylacetone hydrochloride (1.86g, lOnunol) and ethyl isocyanate (l.Og, 14.1 mmol) in acetone (100ml) at 0°C with stirring. After 1 h the solution is filtered, the acetone is evaporated, and the residue recrystallized from aqueous ethanol to give the product (l.Og, 50%), m.p. 215-217°C. Similarly prepared in 61% yield is l,4-dimethyl-5-phenylimidazolin-2-one. 

Various Side-chain Reactions.—2-(2-Thienyl)ethyl isocyanate has been prepared from the corresponding primary amine, carbonyi suiphide, and. S-ethyl chloro-thioformate. Cyclization of 2-(2-thienyl)ethyl isothiocyanate with methyl fluorosulphonate or triethyloxonium tetrafluoroborate gave (178a) and (178b), respectively. The 3-thienyl isomer reacted in the same way. Monoesters of aliphatic dicarboxylic acids and 2-(2-thienyl)ethanol have been prepared in con-... 

Materials and Purification. Chemicals were purchased from Aldrich chemical company and used as received unless otherwise noted 1,1,1,3,3,3-hexamethyl disilazane, ethylene glycol, triphosgene, poly(ethylene oxide) (MW = 600), poly(tetramethylene oxide) (MW = 1000), poly(caprolactonediol) (MW = 530), toluene diisocyanate (TDI), anhydrous ethanol (Barker Analyzed), L-lysine monohydride (Sigma) and methylene bis-4-phenyl isocyanate (MDI) (Kodak). Ethyl ether (Barker Analyzer), triethylamine and dimethyl acetamide were respectively dried with sodium, calcium hydride and barium oxide overnight, and then distilled. Thionyl chloride and diethylphosphite were distilled before use. 

Various methods and reagents have been used to effect the interconversion between meso-ionic isomers 304 305 including (i) heating in protic solvents such as ethanol or ethyl mercaptan, - (ii) treatment with hot ethanolic ammonia or ethanolic sodium hydroxide, - (iii) heating, (iv) heating with aryl isocyanates or isothiocyanates. ... 

To a solution of 298 gm (8 equivalents) of hydrazine in ether is slowly added with stirring and cooIing215 gm (1.15 moles) of 3,4-dichlorophenyl isocyanate in 2 liters of ether while keeping the temperature at 20°C. After the addition the ether layer is decanted from the oily layer. On dilution of the oily layer with water is obtained 237.5 gm of a solid. Recrystallization from ethanol and filtration to remove the insoluble l,6-bis(3,4-dichlorophenyl)biurea afford 108.6 gm of a solid, m.p. 175°-177°C. An additional recrystallization from 700 ml of ethyl acetate affords 77.3 gm (30%), m.p. 173°175°C, ir 3.00, 3.10 p. (NH), 5.90 jji (C=0). 

When an o-nitroaniline is acylatcd by ethyl chloroformate and then catalyti-cally reduced, thermolysis of the reduction product (33) gives a 1-substituted 2-benzimidazolone (34) (Scheme 2.1.15) f99J. Presumably the carbamates (33) eliminate ethanol as they cyclize. and so the reactions bear similarities to those which proceed through isocyanates (see Scheme 2.1.18). In the presence of magnesium chloride, which appears to activate the urea carbonyl group to solvolysis and condensation, some benzimidazolones are converted into 2-alkyl- and 2-arylbenzimidazoles [100],... 

Nitrosolysis of camphor ethyl acetal with ethanolic ethyl nitrite in sulphur dioxide yields the orthoester oxime (205) which is rapidly dehydrated by excess acetal to the orthoester nitrile which then reacts with sulphur dioxide to form the ester nitrile and diethyl sulphite.Further papers in this section include the full paper on ozonolysis of silyl ethers (Vol. 5, p. 33), another synthesis of camphor-enol trimethylsilyl ether (cf. Vol. 6, p. 41)/°° the conversion of camphor oxime with Grignard reagents into the corresponding imine with no aziridine formation/° the preparation of (206) by treating bornylene with trichloroacetyl isocyanate/ the oxidation of thiocam-phor to the 5-oxide and alkylation in the presence of thallium(i) ethoxide to a/S-unsaturated sulphoxides/ and the free-radical C-3 alkylation of camphor with alkenes. " ... 

Perhydropyrido[l,2-c]pyrimidine-l,3-diones were prepared in the reaction of alkyl 2-piperidineacetate with ethyl urethane in diethyl ether in the presence of sodium (56CB1642), by heating with KOCN in hydrochloric acid (59CB637 64JMC146). l-Thioxoperhydropyrido[l,2-c] pyrimidin-3-one was obtained when ethyl 2-piperidine acetate was reacted with KSCN in acidified ethanol (59CB637). Reaction of methyl 2-piperidyl acetate with aryl isocyanates yielded 2-arylperhydropyrido[l,2-c]pyrimidine-... 

ABSOLUTE ALCOHOL or ABSOLUTE ETHANOL (64-17-5) Forms explosive mixture with air (flash point 55°F/13°C). Reacts, possibly violently, with strong oxidizers, bases, acetic anhydride, acetyl bromide, acetyl chloride, aliphatic amines, bromine pentafluoride, calcium oxide, cesium oxide, chloryl perchlorate, disulfuryl difluoride, ethylene glycol methyl ether. Iodine heptafluoride, isocyanates, nitrosyl perchlorate, perchlorates, platinum, potassium- er -butoxide, potassium, potassium oxide, potassium peroxide, phosphonis(III) oxide, silver nitrate, silver oxide, sulfuric acid, oleum, sodium, sodium hydrazide, sodium peroxide, sulfmyl cyanamide, tetrachlorosilane, i-triazine-2,4,6-triol, triethoxydialuminum tribromide, triethylaluminum, uranium fluoride, xenon tetrafluoride. Mixture with mercury nitrate(II) forms explosive mercury fulminate. Forms explosive complexes with perchlorates, magnesium perchlorate (forms ethyl perchlorate), silver perchlorate. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

Many acrylic copolymers are currently used in the textile industry as binders for nonwoven fabrics. The purpose of these fibers is to stabilize the material. In many instances, these copolymers are used in conjunction with amino resins. Casanovas and Rovira have done a study of methyl methacrylate-ethyl acrylate-N-methylol-acrylamide by PY/GC-MS. Among the products identified were methane, ethylene, propene, isobutene, methanol, propionaldehyde, ethanol, ethyl acetate, methyl acrylate, methyl isobutyrate, ethyl acrylate, methyl methacrylate, n-propyl acrylate, and ethyl methacrylate. In this sample, clearly monomer reversion is the primary degradation process occurring however, several other degradation mechanisms are at work. When the sample contains an amino resin in the mixture, acrylonitrile is observed in the pyrogram. Another effect of the amino presence was a marked increase in the amount of methanol detected. Other products detected were meth-oxyhydrazine, methyl isocyanate, and methyl isocyanide. 

Double ring closure. 3 moles methyl isocyanate and a little ethanolic 10%-KOH added to an ethereal suspension of ethyl o-hydroxylaminobenzoate 3a-methylcarbamyloxy - 2,5 - dioxo -3,4- dimethyl-3,3a, 4,5-tetrahydro-2H-l, 2,4-oxadi-azolo[2,3-a]quinazoline. Y 82%. F. e. s. L. Capuano, W. Ebner, and J. Schrepfer, B. 103, 82 (1970). 

N-Substituted esters of carbamic acid (carbamic acid is the mono-amide of carbonic acid) are compounds containing the -NHCOOR group, and are named carbamates or urethanes. Urethane (or urethan) is also used as a name for ethyl carbamate 515, NH2COOEt (a compound which has been shown to act as a carcinogen in some animals), and sometimes even for the whole class of carbamate esters. It is formed by reaction of ethanol with isocyanic acid 516 or urea 517. Since "urethane nomenclature may be confusing there is litde justification in its continued use. 

Protection and Deprotection.—N-Protected a-amino-acids are readily esterified by methanol or ethanol in 60—80% yield after reaction with an enamine (e.g. from isobutyraldehyde and piperidine) and t-butyl isocyanate. Such amino-acids can also be esterified efficiently with alkyl halides under phase-transfer conditions with no racemization. Direct esterification of a-amino-acids with ethyl toluene-p-sulphonate in boiling ethanol gives a-amino-acid ethyl esters in 80—90% yield as the sulphonate salts. The protection of acid functions by formation of the 2-chloro-(or bromo-)ethyl esters has been discussed. These derivatives survive exposure to both moderately acidic and basic conditions and are removable by conversion into the iodoethyl analogues followed by zinc reduction. Alternatively, they may be converted into hydrophilic ammonium or phosphonium salts which exhibit enhanced acid stability but which are cleaved by very dilute base. Yet another method for the removal of such groups using supernucleophilic Co phthalocyanin anions has been reviewed. Further routes to 2,2,2-trichloroethyl esters have been described, one of which employs an activated ester intermediate and is suited to acid-labile substrates. 

Ethyl carbamate in wine is formed (mostly at the end of fermentation) from urea. The intermediates of its degradation are probably cyanates and cyanic acid (HO-C=N), also known as hydrogen cyanate, which may isomerise to isocyanic acid (H-N=C=0). Iso-cyanic acid can also arise by protonation of the cyanate anion and nucleophilic addition of ethanol to isocyanic acid yields ethyl carbamate. Isocyanic acid also reacts with other nucleophilic reagents, such as water (with formation of ammonia and carbon dioxide), thiols and amino groups of proteins. By catalysis with ornithinecar-bamoyl transferase, citrulline is transformed into ornithine and carbamoyl phosphate, the ethanolysis of which yields ethyl carbamate (Figure 12.39). 

The reaction of alkyl bromides or alkyl iodides with potassium cyanate in DMF is a very useful method to synthesize many aliphatic isocyanate trimers. The reaction of aromatic isocyanates with ethanol in the presence of A-methylmorpholine is another useful synthetic method to produce aromatic isocyanate trimers. The initially formed ethyl carbamate is an intermediate in the trimerization reaction. 

The highly ring strained cyclopropanone (which is conveniently stored and used as a mixed ketal) also undergoes Schmidt chemistry to afford M-substituted jS-lactams along with ethyl carbamates in about a 1 1 ratio (Scheme 7.9). Presumably, the p-laclam is formed via the typical ring expansion mechanism described above. Ethyl carbamates are more mechanistically intriguing, requiring the formal loss of ethylene and N2 followed by recombination of a silylated isocyanate with ethanol. 

In hot ethanol, benzoyl azide was converted to ethyl A-phenylcarbamate (1894). This Curtius rearrangement was recognized by its discoverer as a general method of degrading carboxylic acids to amines, whereas the intermediacy of isocyanates escaped him. 

Dimethyl formamide Dimethyl sulfoxide Ethanol Ethyl benzene Formaldehyde Isocyanates Isopropyl alcohol MEK... 

---