Alcohols 2- ethyl chloroformate

Ethyl chloroformate is a corrosive, flammable liquid with a boiling point of 95 Celsius. It is practically insoluble in water, but slowly decomposed by it. Ethyl chloroformate is miscible with alcohol, benzene, chloroform, and ether. It can be prepared by reacting phosgene with ethyl alcohol. Ethyl chloroformate is commercially available. 

The continuous production of high purity methyl or ethyl carbonate from the alcohol and chloroformates has been patented (80). Chloroformate and alcohol are fed continuously into a Raschig ting-packed column in which a temperature gradient of 72—127°C is maintained between base and head of the column HCl is withdrawn at the head, and carbonate (99%) is withdrawn at the base. 

Small quantities of ethyl alcohol stabiLhe chloroform during storage. Various other stabiLhers have been proposed, eg, CH2=CHCH2CH2CN and metbacrylonitrile (6). 

In the sjmthesis of evodiamine effected by Asahina and Ohta,i N-methylanthranilic acid was converted by ethyl chloroformate into N-methylisatoic anhydride, which, on treatment with 3- -aminoethylindole, furnished 3-/3-o-methylaminobenzoylaminoethylindole (III), and this with ethyl orthoformate at 175-180° gave dZ-evodiamine, m.p. 278°, convertible by boiling alcoholic hydrogen chloride into Zsoevodiamine, m.p. 147°, as shown above. 

The synthesis of key intermediate 12, in optically active form, commences with the resolution of racemic trans-2,3-epoxybutyric acid (27), a substance readily obtained by epoxidation of crotonic acid (26) (see Scheme 5). Treatment of racemic 27 with enantio-merically pure (S)-(-)-1 -a-napthylethylamine affords a 1 1 mixture of diastereomeric ammonium salts which can be resolved by recrystallization from absolute ethanol. Acidification of the resolved diastereomeric ammonium salts with methanesulfonic acid and extraction furnishes both epoxy acid enantiomers in eantiomerically pure form. Because the optical rotation and absolute configuration of one of the antipodes was known, the identity of enantiomerically pure epoxy acid, (+)-27, with the absolute configuration required for a synthesis of erythronolide B, could be confirmed. Sequential treatment of (+)-27 with ethyl chloroformate, excess sodium boro-hydride, and 2-methoxypropene with a trace of phosphorous oxychloride affords protected intermediate 28 in an overall yield of 76%. The action of ethyl chloroformate on carboxylic acid (+)-27 affords a mixed carbonic anhydride which is subsequently reduced by sodium borohydride to a primary alcohol. Protection of the primary hydroxyl group in the form of a mixed ketal is achieved easily with 2-methoxypropene and a catalytic amount of phosphorous oxychloride. 

Solubilities Soluble in toluene, acetone, ether, chloroform. Slightly soluble in alcohols, ethyl acetate. Insoluble in water... 

Using ethyl chloroformate as a reagent for C-8—N bond cleavage (Section II,A,4), synthesis of ( )-canadaline (272) from tetrahydroberberine (26) was independently achieved by Ronsch (40) and Hanaoka et al. (41,45). Bond-cleaved iodide 40a or chloride 40b was converted to the acetate 280 or the alcohol 281, both of which were easily derivatized to 272 through reduction of the urethane and oxidation of the alcohol 274 (Scheme 48). 

The cycloberbine 339 derived from coptisine (65) was reduced with lithium aluminum tri-tert-butoxyhydride to afford the trans-alcohol 340 along with a small amount of the cis-alcohol (Scheme 62). Treatment of 340 with ethyl chloroformate effected C-8—N bond cleavage and simultaneous oxyfunc-tionalization at C-8 with the desired stereochemistry to produce the oxazolidinone 341. This was hydrolyzed with potassium hydroxide and then underwent N-methylation to give ( )-ochrobirine (343). Similarly, the ochrobirine analog 344 was also obtained from berberine (15) (171). 

The cyclobutanone (255) reacted with acid to furnish the keto-acid (259). Upon esterification, ketalization and reduction, (259) was converted to the alcohol (260). Mesylation of the alcohol (260) and then treatment of the mesylate with NaN3 in DMSO provided the azide (261). The azide (261) was then transformed to the urethane (262) by reduction and ethyl chloroformate reaction. The urethane (262) was deketalized by acid, nitrosated by N204—NaOAc and decomposed by NaOEt—EtOH to give the ketone (263) 89). The ketone (263) served as a starting material for the synthesis of veatchine (264)90). 

One application in liquid chromatography which does alter the separation process is the use of a specific series of derivatives to enable the separation of chiral (optical isomers) forms of alcohols, amines and amino acids using reverse-phase separation. FLEC is available in the two chiral forms (+)-l-(9-fluorenyl) ethyl chloroformate and (—)-l-(9-fluorenyl) ethyl chlorofor-mate (Figure 3.12). Reaction of two stereoisomers of a test compound (e.g. T+ and T—) with a single isomer of the derivatizing reagent (e.g. R+) will result in the formation of two types of product, T+R+ and T—R+. It is possible to separate these two compounds by reverse-phase chromatography. 

The chemistry and procedures for modification of the - CO2H groups of PAA hyperbranched grafts on PE powder were analogous to those used for PAA grafts on PE or PP films and wafers. For example, a 90% yield in ester formation was possible using acid-catalyzed Fisher esterification. Likewise, quantitative reduction (ethyl chloroformate activation, borane-dimethyl sulfide reduction) to hyperbranched poly(allyl alcohol)s and amidation all could be carried out using procedures like those used for PAA/Au surfaces. 

The solvents most commonly employed are water, ethyl and methyl alcohol, ether, benzene, petroleum ether, acetone, glacial acetic acid also two or three solvents may be mixed to get the desired effect as described later. If you still cannot dissolve the compound, try some of these chloroform, carbon disulfide, carbon tetrachloride, ethyl acetate, pyridine, hydrochloric acid, sulfuric acid (acids are usually diluted first), nitrobenzene, aniline, phenol, dioxan, ethylene dichloride, di, tri, tetrachloroethylene, tetrachloroethane, dichloroethyl ether, cyclohexane, cyclohexanol, tetralin, decalin, triacetin, ethylene glycol and its esters and ethers, butyl alcohol, diacetone alcohol, ethyl lactate, isopropyl ether, etc. 

To increase the yields of the ring closure reactions, a new method was developed that was successfully applied for the synthesis of alicyclic fused systems of both the parent oxazolidine-2-thione and tetrahydro-1,3-oxazine-2-thione (85S1149). As an example, the synthesis of 2-thioxoperhydro-l,3-benzoxazine 103 is described. The dithiocarbamate 101, prepared from the amino alcohol 100, carbon disulfide and triethylamine, was treated with ethyl chloroformate in the presence of triethylamine, to give the thioxo derivative 103 via the transition state 102 (85S1149). In this way, the fused-skeleton thioxooxazines (91, X = S, 92) can be prepared with considerably higher yields (50-70%) than by the earlier methods (85S1149). 

Distilled with chloride of lime, ethylic alcohol produces chloroform. 

Ethyl orthoformate is prepared in 45 % yield by adding sodium metal por-tionwise to a mixture of excess absolute alcohol and chloroform [118]. (See Kaufmann and Dreger [118] for earlier references to this reaction.)... 

Compound Name Ethylhexaldehyde N-Propyl Alcohol Diethyl Carbonate Ethyl Chloracetate Ethyl Chloride Ethyl Chloroacetate Ethyl Chloroformate Ethyl Chloroacetate Ethyl Chloroacetate Ethyl Phosphorodichloridate Ethyldichlorosilane Ethylene... 

The solubility of nitroguanidine in organic solvents is limited. Desvergnes [31] determined its solubility in various solvents water, acetone, methyl and ethyl alcohols, ethyl acetate, ether, benzene, toluene, pyridine, chloroform, carbon tetrachloride and carbon sulphide. In all these liquids the solubility of nitroguanidine is negligible, the highest value—for pyridine—being 1.75 g/100 ml at 19°C. 

Acid chlorides. The corresponding acid and hydrogen chloride are the most likely impurities. Usually these can be removed by efficient fractional distillation. Where acid chlorides are not readily hydrolysed (e.g. aryl sulphonyl chlorides) the compound can be freed from contaminants by dissolving in a suitable solvent such as alcohol-free chloroform, dry toluene or petroleum ether and shaking with dilute sodium bicarbonate solution. The organic phase is then washed with water, dried with sodium sulphate or magnesium sulphate, and distilled. This procedure is hazardous with readily hydrolysable acid chlorides such as acetyl chloride and benzoyl chloride. Solid acid chlorides are satisfactorily crystallised from toluene, toluene-petroleum ether, petroleum ethers, alcohol-free chloroform/toluene, and, occasionally, from dry ethyl ether. Hydroxylic or basic solvents should be strictly avoided. All operations should be carried out in a fume cupboard because of the irritant nature of these compounds. 

ALCOHOLS Allyltrimethylsilane. (1,5-Cyclooctadiene)bis(methyldiphenylphos-phine)iridium hexafluorophosphate. Guaiacylmcthyl chloride. Lcvulinic acid. (3-( Primethylsilyljethoxymethyl chloride. 2-(Trimethylsilyl)ethyl chloroformate. Trimelhyllrityloxysilane. 

Ethyl-M-methylcarbamate has been prepared by adding aqueous methylamine to ethyl chloroformate 1 and from methyl car-bamyl chloride and ethyl alcohol.2... 

Nitroglycerine is readily dissolved in most organic solvents and itself behaves as a good solvent. Thus, it is completely miscible in all proportions at room temperature with the following liquids methyl alcohol, ethyl acetate, anhydrous acetic add, benzene, toluene, xylenes, phenol, nitrobenzene, nitrotoluenes, pyridine, chloroform, dichloroethane, dichloroethylene, and the like. 

The carboxyl group of 4-oxo-4//-pyrimido[2,l-a]isoquinoline-3-carboxylic acids was esterified with various alcohols [84JAP(K)84/172490] and was converted into N-substituted 3-carboxamides by treatment with ethyl chloroformate in the presence of triethylamine in methylene chloride, followed by amines and hydroxylamine at 0°C [84JAP(K)84/172490 85EUP143001]. 

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