Orthoester


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Orthoester

 

RC(OR′)3, an ester of carboxylic orthoacids, RC(OH)3, where R is an organic radical or hydrogen. In contrast to orthoacids, orthoesters are stable compounds. The simplest occur as colorless liquids with an ethereal odor and are nearly insoluble in water but readily soluble in organic solvents. Orthoesters readily hydrolyze in a weak acid medium but remain stable in alkaline media. One method of obtaining orthoesters is to react 1,1,1-trihalide hydrocarbons with alcoholates of alkali metals, for example, HCCl3 + 3NaOC2H5 → HC(OC2H5)3 + 3NaCI. Orthoesters are useful in organic chemistry, for example, orthoformic acid esters are used in the synthesis of acetals, aldehydes, and ketones.

References in periodicals archive ?
Keywords: Quinazolin-4(3H)-one, Microwave, SbCl3, Solvent-free, Orthoester.
Anthranilic acid (4) (10 mmol), orthoester (2) (12 mmol), ammonium acetate (14mmol) and catalytic amounts of SbCl3 were mixed thoroughly in a microwave reactor, equipped with a condenser.
Summary: Efficient and fast condensation of anthranilic amide or anthranilic acid with various orthoesters have been carried out using a catalytic amount of Antimony(III) chloride (SbCl3) under microwave irradiation to afford a series of 2-substituted quinazolin-4(3H)-ones in good to excellent yields under solvent free condition.
7] Among these methods, the condensation of the anthranilic amide or anthranilic acid with orthoesters is a classical procedure.
There is a recent approach to the synthesis of 2- substituted quinazolin-4(3H)-ones via the condensation of 2-aminobenzamide and orthoesters with by Huang et al.
DDs are believed to be derived from a tigliane precursor and have an orthoester motif, though a very large number of DDs were identified, they occurred only in the plant families of Thymelaeaceae and Euphorbiaceae (Evans and Soper, 1978).
The potent irritancy of the daphnane orthoester, resini feratoxin, exhibits features of a mixed aetiology.
Daphnane-type diterpenoids (DDs) are the main types of plant diterpene orthoesters known and have remarkable biological activities.
Antiviral chlorinated claphnane diterpenoid orthoesters from the bark and wood of Trigonostemon cherrieri.
Furthermore, the biodegradability of these polymers can be easily manipulated by incorporating a variety of labile groups such as ester, orthoester, anhydride, carbonate, amide, urea, and urethane in their backbone.
The Patent Office rejected the compositions claims as obvious, reasoning that the combination of tetra-orthoesters and hydrocarbon fuel was suggested, albeit for a different purpose, by the known tri-orthoester fuel combinations and the structural similarity of the two types of orthoesters.
In a previous communication, hetero- cyclization of 7-hydrazinyl-5-methyl-1-phenyl-3- phenyldiazenyl-1H-pyrimido [4,5-e] [1,3,4] thiadiazine 2f with orthoesters was studied by NOE technique and it showed that 1H-[1,2,4] triazolo[4',3':1,2]pyrimido[4,5-e][1,3,4]thiadiazines have been formed as sole product [16] (Scheme 2).