Ethyl Formate Method

Method 3 (F. Adickes, 1930). The experimental procedure is similar to that described in Method 2 except that excess of ethyl formate (b.p. 

One litre of commercial absolute alcohol (or any ethyl alcohol of 99 per cent, purity or better) is treated with 14 g. of clean, dry sodium when the sodium has completely reacted, 40 g. of pure ethyl formate are added. The mixture is refluxed for 2-3 hom , and the dry alcohol is distilled oflF as in Method 2 the first 25 ml. of distillate are discarded. The super-dry alcohol contains about 0 03 per cent, of water. 

Successful results have been obtained (Renfrew and Chaney, 1946) with ethyl formate methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec.-butyl and iso-amyl acetat ethyleneglycol diacetate ethyl monochloro- and trichloro-acetates methyl, n-propyl, n-octyl and n-dodecyl propionates ethyl butyrate n-butyl and n-amyl valerates ethyl laurate ethyl lactate ethyl acetoacetate diethyl carbonate dimethyl and diethyl oxalates diethyl malonate diethyl adipate di-n-butyl tartrate ethyl phenylacetate methyl and ethyl benzoates methyl and ethyl salicylates diethyl and di-n-butyl phthalates. The method fails for vinyl acetate, ieri.-butyl acetate, n-octadecyl propionate, ethyl and >i-butyl stearate, phenyl, benzyl- and guaicol-acetate, methyl and ethyl cinnamate, diethyl sulphate and ethyl p-aminobenzoate. 

The one-carbon fragment is ethyl formate. This reaction is important as a method of control since it occurs only on one side of the carbonyl group that is it is regioselective. The reason is that this product can itself enohse in... 

The methine chain is obtained by reacting ethyl o-formate (method A ) or ethylisoformanilide (method B) with a bis quaternary salt of bis-(2-thiazolyllbutane. Concerning dyes with fused thiazolo rings pyrrolo[2. lb]thiazoIe. thiazolo[2.3a]indole. thiazolo[2.3c]1.4-benzox-azine. the a carbon directly linked to the carbon 2 of the thiazoJe ring is also responsible for the classical syntheses giving trimethine or penta-methine dyes. 

The mechanism of the condensation in Part D probably involves thioformylation of the metallated isocyanoacetate followed by intramolecular 1,1-addition of the tautomeric enethiol to the isonitrile. This thi2izole synthesis is analogous to the formation of oxazoles from acylation of metallated isonitriles with acid chlorides or anhydrides. " Interestingly, ethyl formate does not react with isocyanoacetate under the conditions of this procedure. Ethyl and methyl isocyanoacetate have been prepared in a similar manner by dehydration of the corresponding N-formylglycine esters with phosgene and trichloromethyl chloroformate, respectively. The phosphoryl chloride method described here was provided to the submitters by Professor U. Schollkopf and is based on the procedure of Bohme and Fuchs. The preparation of O-ethyl thioformate in Part C was developed from a report by Ohno, Koi/.uma, and Tsuchihaski. " ... 

Water, ethyl alcohol and carbon tetrachloride form a ternary mixture boiling at about 61 °. This vapor mixture, on condensation, separates into two phases the heavier liquid consists of carbon tetrachloride and alcohol with only small amounts of water the lighter liquid consists of approximately 65 per cent alcohol, 25 per cent water and 10 per cent carbon tetrachloride. By taking advantage of this fact, it is possible to conduct the esterification at a temperature so low that the ethyl hydrogen oxalate first formed does not decompose into ethyl formate and other products, as is the case when the customary methods of esterification are employed. 

Serine has been prepared by the Strecker method from glycol-aldehyde 1 and from ethoxyacetaldehyde,2 3 by the condensation of ethyl formate with ethyl hippurate followed by reduction and hydrolysis,4 5 from the reaction product of chloromethyl ether with ethyl sodium phthalimidomalonate,6 and by amination of a-bromo-/3-methoxypropionic acid with subsequent demethyla-tion.7... 

In Ref 2 is described analysis of industrial EtAcet liable to contain water, ethanol and ethyl formate with traces of acidity, whereas in Ref 3 is described a precise method for detn of acidity in EtAcet... 

We have previously seen (0-96) that dianions of carboxylic acids can be alkylated in the a position. These ions can also be acylated on treatment with a carboxylic ester1705 to give salts of p-keto acids. As in 0-96, the carboxylic acid can be of the form RCH2COOH or RR"CHCOOH. Since p-keto acids are so easily converted to ketones (2-40), this is also a method for the preparation of ketones R COCHiR and R COCHRR", where R can be primary, secondary, or tertiary alkyl, or aryl. If the ester is ethyl formate, an a-formyl carboxylate salt (R = H) is formed, which on acidification spontaneously de-carboxylates into an aldehyde.1706 This is a method, therefore, for achieving the conversion RCH2COOH — RCH2CHO, and as such is an alternative to the reduction methods discussed in 0-83. When the carboxylic acid is of the form RR CHCOOH. better yields are obtained by acylating with acyl halides rather than esters.1707... 

A. 2-Hydroxymethylenecyclohexanone, Method 1. A mixture of 23 g. (1 g.-atom) of sodium metal cut in approximately 1-cm. cubes, 2 1. of dry ether, 98 g. (103 ml., 1 mole) of redistilled cyclohexanone, and 110 g. (120 ml., 1.5 moles) of ethyl formate is placed in a 5-1. three-necked flask equipped with a stirrer, stopper, and vent tube. The reaction is initiated by the addition of 5 ml. of ethyl alcohol to the stirred mixture, which is then placed in a cold water bath. Stirring is continued for 6 hours. After standing overnight, 25 ml. of ethyl alcohol is added, and the mixture is stirred for an additional hour. After the addition of 200 ml. of water, the mixture is shaken in a 3-1. separatory funnel. The ether layer is washed with 50 ml. of water, and the combined aqueous extracts are washed with 100 ml. of ether. The aqueous layer is acidified with 165 ml. of 6N hydrochloric acid, and the mixture is extracted twice with 300 ml. of ether. The ether solution is washed with 25 ml. of saturated sodium chloride solution and then is dried by (he addition of approximately 30 g. of an-... 

The first synthesis of pterocarpan was accomplished. by Suginome and Iwadare (60BCJ567). 2 -Hydroxyisoflavone, prepared from 2,2 -dihydroxydeoxybenzoin with ethyl formate and sodium, was reduced either with sodium borohydride or LAH to yield a mixture of stereoisomeric 2 -hydroxyisoflavan-4-ols. Treatment of this mixture with acid under mild conditions gives pterocarpan (Scheme 51). Racemic pterocarpin has also been prepared by this method (67ABC1490). 

The same one-carbon unit has been employed in a convenient isoflavone synthesis from deoxybenzoins (76S326). Other methods of ring closure of phenyl benzyl ketones to this heterocycle have been reviewed (B-62MI22400) and include triethyl orthoformate (56PIA(A)(44)36), zinc cyanide (58CB2858), ethyl formate (80BCJ831) and ethoxalyl chloride (70JCS(C)1219). 

The critical temperatures and pressures have been measured for acetic anhydride and ethyl formutc The critical density is uvailabk only for ethyl formate. The method of Riedel1 was used lo estimate the critical temperatures and pressures of propionic acid and isopropyl acetate Vowlcs method was used to calculate the critical densities 1... 

Stull Mimmun/cs the data available on the vapor pressures of acetic anhydride and ethyl formate from the melting point to tile critical point, and for propionic anhydride and isopropyl acetate up to the boiling point 1 The vapor pressures ubove the boiling point were estnriuccd by a previously described method ... 

The liquid heat capacities have been determined at 20 C for acetic anhydride and propionic anhydride J The heat ca polities of ethyl formate and acetic anhydride urc presented using (lie constants to (lie equation presented by Lyman and Danner.37,3 The method uf Yuan and Sieil 0- has been used to determine the heat capacity of Isopropyl acetate. The data for propionic anhydride were extended by the equation heat capacity iime density equals a constant... 

Data arc available from O C to the critical point for ethyl formate. from tTC to 140 C for acetic anhydride.W w n and at room temperature for propionic anhydride. Sudden s method ho been used to calculate the surface tensions at other temperature. ... 

Another method is the use of esters as alkylating agents in triflic acid172 [Eq. (4.44)]. This method has been used to synthesize. S -methylated phenylene sulfide oligomers (methyl triflate, triflic acid, 25°C, 10 h) and to solubilize poly(phenylenesulfide) by transforming it to poly(arylenesulfonium) salts 62 (methyl triflate, methyl or ethyl formate, triflic acid, 110°C, lOh). In a similar way, alkylation of thianthrene to yield the corresponding sulfonium salts (63) has been achieved using alkyl formates.173... 

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