Formic acid esters

The HSAB pattern may also be reversed by steric effects a Japanese patent describes the preparation of 3-(4-R-thiazolyl-2)thioallophanic acid esters (151) by reaction between 2-amino-4-R-thiazoles (4-R = H or low alkyl) and isothiocyanate formic acid ester (Scheme 96) (309). 

Preparation of y-pyrone by the reaction of methoxybutenone with formic acid esters (10°C, MeONa, CgHe, 1.5 h) has been reported (73 JPP7229512 80MI2). The intermediate 292 undergoes [3,3]-sigmatropic rearrangement to form methoxydi-hydropyrone 293 which further eliminates methanol, thus transforming to y-pyrone. 

Linalyl Formate.—The formic acid ester of linalol, CjqHj OOCHj, has a distinctive odour somewhat resembling that of the acetate. It is an oil boiling at 189° to 192°, and is prepared by treating linalol with formic acid, but the reaction is not complete and commercial samples are never pure esters. 

Terpinyl Formate.—The formic acid ester of terpineol, CjeHj-OOCH, occurs naturally in Ceylon cardamom oil. It is prepared artificially by... 

Formic acid (Ester of formic acid) Alkyl formate... 

These X -phosphorins 720 a-c also fail to react with carbonyl compounds. However, they are attacked by electrophiles (H or alkyl cations) at the C—2 position. In this manner new 1,1-diphenyl-2,3-benzo-X-phosphorins which are sustituted at positions C—2 (and C-4) can be prepared. Diazonium ions attack at C—4 to form azocompounds if an excess is used, C—2 is also substituted Hydrolysis with hot water affords 747. The reaction with ortho-formic acid ester forms a cyanine dye having a bridge at the C—4 positions 142 The experimen-... 

Fulminic acid can be regarded as the simplest oxime. A number of compounds with an oxime group C=NOH can form salts which possess initiating properties, for example salts of nitroformoxime (methylnitrolic acid) (I) which can be obtained in a known way by the action of nitrous acid on nitromethane. Salts of form-hydroxamic acid (II), particularly the mercuric salt, also possess initiating properties [66]. Formhydroxamic acid can be obtained by the action of hydroxylamine on formic acid esters or by oxidation of methylamine. 

The solubility of high-nitrated cellulose (13.46% N) in a mixture of formic and acetic acid esters with ethyl alcohol was followed by T. Urbanski [51]. The author established that for a range of homologous esters of both acids, the capacity of dissolving nitrocellulose increased in proportion with the value of the dipole moment of the ester. According to T. Urbanski the sequence of formic acid esters corresponding with an increasing capacity to dissolve nitrocellulose is paralleled by the dipole moment values, as follows ... 

Acyl anions (RC(=0)M) are unstable, and quickly dimerize at temperatures >-100 °C (Section 5.4.7). These intermediates are best generated by reaction of organolithium compounds or cuprates with carbon monoxide at -110 °C and should be trapped immediately by an electrophile [344—347]. Metalated formic acid esters (R0C(=0)M) have been generated as intermediates by treatment of alcoholates with carbon monoxide, and can either be protonated to yield formic acid esters, or left to rearrange to carboxylates (R0C(=0)M —> RC02M) (Scheme 5.38) [348]. Related intermediates are presumably also formed by treatment of alcohols with formamide acetals (Scheme 5.38) [349]. More stable than acyl lithium compounds are acyl silanes or transition metal acyl complexes, which can also be used to perform nucleophilic acylations [350],... 

One can also acetalize carbonyl compounds completely without using the alcohol in excess. This is the case when one prepares dimethyl or diethyl acetals from carbonyl compounds with the help of the ortho formic acid esters trimethyl ortho formate HC(OCH3)3 or triethyl ortho formate HC(OC2H5)3, respectively. In order to understand these reactions, one must first clearly understand the mechanism for the hydrolysis of an orthoester to a normal ester (Figure 9.13). ft corresponds nearly step by step to the mechanism of hydrolysis of 0,0-acetals, which was detailed in Figure 9.12. The fact that the individual steps are analogous becomes very clear (see Figure 9.13) when one takes successive looks at... 

The C=0 double bond of esters is usually not electrophilic enough to be olefinated by P ylides. Only formic acid esters can undergo condensation with Ph3P -CH2 and then they give enol ethers of the structure H—C(=CH2)—OR. a,/3-Unsaturated esters can sometimes react with P ylides, but this then results in a cyclopropanation ... 

Later, they also reported an intermolecular hydroacylations of 1,3-dienes with aromatic aldehydes yielding the corresponding j8,y-unsaturated ketones (Eq. 51) [79]. This reaction does not require a CO atmosphere. The addition of formyl C-H bond in formic acid esters and amides to olefins and conjugate... 

Dimethylformamide was suggested for the GC detection of microgram amounts of formic acid [182]. After esterification of acids with diazomethane the sample was treated with a dimethylamine—water mixture (1 2). Dimethylformamide was thus produced from formic acid ester, while other acids present were analysed as methyl esters. 

From Acetic and Formic Acids.—A fourth method of synthesis from acetic and formic acid esters will be explained in detail in connection with the next acid. All of these syntheses prove the constitution of pyro-racemic acid as an a//>/fa-ketone acid as given. It may be considered as aceto formic acid which is in accord with the fourth method of synthesis. As an acid it forms all acid derivatives and as a ketone it undergoes the characteristic ketone reactions, e.g.y with phenyl hydrazine and hydroxyl amine. On heating to 150° with dilute sulphuric acid in a sealed tube it loses carbon dioxide and yields acet aldehyde. 

As in the Grignard reaction we may use any aliphatic aldehyde, ketone, ester or acid chloride, or an aryl compound of the same type and also, we may use either alkyl magnesium halides or aryl magnesium halides the synthesis makes possible the preparation of practically any desired secondary or tertiary alcohol either aliphatic or aromatic. Also if formaldehyde, in the form of its polymer, tri-oxy methylene, is used in the second reaction we will obtain primary alcohols. In the third reaction formic acid esters yield secondary instead of tertiary alcohols. These syntheses of alcohols by the Grignard reaction give us an idea of its importance in synthetic work. 

Sulfonyl halides (e.g. benzenesulfonyl chloride) form adducts (11) with acid amides in an equilibrium reaction. From these adducts or via adducts of this type 0-sulfonated lactim ethers, isonitriles, adenine, nitriles, amidines, amidinium salts and formic acid esters were prepared. The adducts from DMF and chlorosulfonamides (12) can be used to prepare amidines or amidrazones. A/-Chlorosulfonylcarboxylic acid amides yield nitriles on treatment with DMF or other tertiary amides, presumably via an acid amide sulfonyl chloride complex (13 equation 3). ... 

HCOO—(C) HCOO— connected to C (formic acid ester) 642.0427... 

Watanabe et al. reported that the addition of C-H bonds in aldehydes to olefins took place efficiently with the aid of Ru3(CO)12 under a CO atmosphere at 200°C (Eq. 51) [118]. They also reported that the same ruthenium-carbonyl complex catalyzes the addition of the C-H bonds in formic acid esters and amides to olefins (Eq. 52) [119]. 

The reagent is prepared just as the corresponding trichloride is prepared by reaction of catechol with PBr, and then bromine. It reacts with formic acid esters to give a,a-dibromomethyl alkyl ethers 1... 

These data as presented in the patent are evidently conventionalized and the products designated probably represent characteristic fractions obtained in the distillation of the dry product. Substances not reported but which in all probability are present in the product include methanol, formaldehyde, formic acid, esters, amyl alcohols, and possibly heavier compounds formed by condensation and polymerization. 

The Aldehydic protons of the Formic Acid esters appears as a sharp singlet at low field in the range from 7.9 to 8.10 ppm. 

Formic acid esters from ethylene derivatives C C —CHCOOCH s. 4,162... 

Redox-catalyzed migratory insertion of CO into [FeMe(COXPPh3)Cp] rapidly gives a high yield of [Fe(COMeXCOXPPh3)Cp] (531). Synthesis of formic acid esters via oxidation of [FeH(CO)2Cpj by cerium(IV) or copper(II) in alcohols, ROH, also proceeds via initial one-electron oxidation the paramagnetic formyl [Fe(CHOXCO)(ROH)Cp]+ is implicated as an intermediate (532)2 (Section VII,E). 

Pathway A has already been discussed (2-23). In the reaction sequence C, introduction of the formyl group by a Claisen ester condensation with a formic acid ester is followed by treatment with 4-toluenesulfonyl azide, i. e., by a diazo transfer reaction (Regitz and Menz, 1968 see Sect. 2.6). Mn04 is also frequently used for the synthesis of bis- and tetradiazo compounds from the corresponding bis- and tetrahydrazones (Teki et al., 1986 Hannemann et al., 1988 and references therein). 

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