Grignard reaction chloride

By using a lOOX excess of the metal (less than lOO for experiments on a large scale) one can save much time. Some Grignard reactions, especially those with tertiary alkyl chlorides and cyclohexyl chloride, are not easily started and it seemed desirable, therefore, to inform the user of this book about our experiences. 

TT-Allylpalladium chloride (36) reacts with the nucleophiles, generating Pd(0). whereas tr-allylnickel chloride (37) and allylmagnesium bromide (38) reacts with electrophiles (carbonyl), generating Ni(II) and Mg(II). Therefore, it is understandable that the Grignard reaction cannot be carried out with a catalytic amount of Mg, whereas the catalytic reaction is possible with the regeneration of an active Pd(0) catalyst, Pd is a noble metal and Pd(0) is more stable than Pd(II). The carbon-metal bonds of some transition metals such as Ni and Co react with nucleophiles and their reactions can be carried out catalytic ally, but not always. In this respect, Pd is very unique. 

Excess alkylating reagent is required if the tetraorganotin is desired as the exclusive product. In commercial practice, the stoichiometry is kept at or below 4 1, since the cmde product is usually redistributed to lower organotin chlorides in a subsequent step and an ether is used as the solvent (86). The use of diethyl ether in the Grignard reaction has been generally replaced with tetrahydrofuran. 

Cesium forms simple alkyl and aryl compounds that are similar to those of the other alkah metals (6). They are colorless, sohd, amorphous, nonvolatile, and insoluble, except by decomposition, in most solvents except diethylzinc. As a result of exceptional reactivity, cesium aryls should be effective in alkylations wherever other alkaline alkyls or Grignard reagents have failed (see Grignard reactions). Cesium reacts with hydrocarbons in which the activity of a C—H link is increased by attachment to the carbon atom of doubly linked or aromatic radicals. A brown, sohd addition product is formed when cesium reacts with ethylene, and a very reactive dark red powder, triphenylmethylcesium [76-83-5] (C H )2CCs, is formed by the reaction of cesium amalgam and a solution of triphenylmethyl chloride in anhydrous ether. 

Chromone-2-carbaldehyde, 3-methyl-synthesis, 3, 709 Chromonecarbaldehydes Knoevenagel condensation, 3, 711 Chromone-3-carbaldehydes mass spectra, 3, 615 oxidation, 3, 709 reactions, 3, 712 Schiff bases, 3, 712 synthesis, 3, 821 Chromone-2-carbonyl chloride Grignard reaction, 3, 711 Chromonecarboxamide, N-tetrazolyl-antiallergic activity, 3, 707 Chromone-2-carboxylic acid, 3-chloro-ethyl ester... 

Although cholest-4-en-3-one does not give a 1,4-addition product in the cuprous chloride-catalyzed Grignard reaction,the A ° -5a-2-ketone (35) reacts to give the 10a-methyl-5a-2-ketone (36). ... 

Phthalic anhydride is reacted with phenylacetic acid to form 3-benzylidenephthalide which is then hydrogenated to 2-phenethylbenzoic acid. Conversion to the acid chloride followed by intramolecular dehydrochlorination yields the ketone, 5H-dibenzo[a,d] cyclohepten-5-one. The ketone undergoes a Grignard reaction with 3-(dimethylamino)propyl chloride to give 5-(7-dimethylaminopropylidene)-5H-dibenzo[a,d] cycloheptene. 

The starting material can be prepared in known manner from dibenzo[a,d] cyclohepta-1,4-diene-5-one by a Grignard reaction with 3-dimethylaminopropyl magnesium chloride, hydrolysis and dehydration of the resulting carbinol. 

The ketone, preferably prepared by a Grignard reaction, was added in such a way as to maintain the ether under constant reflux. When all of the solution had been added, the mixture was refluxed for a further hour. The mixture was then allowed to stand for 12 hours at ambient temperature, after which the reaction mass was extracted with ice and ammonium chloride in known manner. 

The mechanism of this Grignard reaction is similar to that of L1AIH4 reduction. The first equivalent of Grignard reagent adds to the acid chloride, loss of (T from the tetrahedral intermediate yields a ketone, and a second equivalent of Grignard reagent immediately adds to the ketone to produce an alcohol. 

Acid chloride—con l d esters from, 802-803 from carboxylic acids, 794-795 Grignard reaction of, 804-805 hydrolysis of, 802 IR spectroscopy of, 822-823 ketones from, 805 mechanism of formation from carboxylic acids, 795 naming, 786... 

In some cases, the Grignard reaction can be performed intramolecularly. For example, treatment of 5-bromo-2-pentanone with magnesium and a small amount of mercuric chloride in THE produced 1-methyl-1-cyclobutanol in 60% yield. Other four- and five-membered ring compounds were also prepared by this procedure. Similar closing of five- and six-membered rings was achieved by treatment of a 6- or s-halocarbonyl compound, not with a metal, but with a dianion derived from nickel... 

A Grignard reaction between cyclohex-2-enone and diisopropyl magnesium chloride was carried out in a micro reactor yielding a keto and enol product each [168],... 

In liquid-solid processes reaction takes place between a liquid reactant and an insoluble or sparingly soluble solid which must be finely divided to speed up the process. Another measure to accelerate the process is to use an aqueous solution of a phase-transfer agent (typically a quaternary ammonium salt). The solid can also be a catalyst for reactions between liquid components, e.g. in acylations, carried out both conventionally in the presence of metal chlorides (mostly AICI3) or catalysed by zeolites and Grignard reactions. 

The methylene group of anthrone 64 is acidic by virtue of doubly vinylic activation by the carbonyl group. Thus, treatment with methyl iodide and base leads to the 9,9-dimethyl derivative 65. Grignard reaction with 6-dimethylaminopropyl magnesium chloride... 

One of these products (49) was used as a key intermediate for the synthesis of the Amaryllidaceae alkaloids a- and /-lycorane (Scheme 12)53. A copper-catalyzed Grignard reaction with 49 afforded 50 via a selective y-anti displacement of the chloride. Hydrogenation followed by Bischler-Napieralski cyclization gave 51. Interestingly, reversal of the latter two steps gave the isomer 52 where an epimerization at the benzylic carbon had occurred in the cyclization step (>99% selectivity). Subsequent reduction of the amide in each case afforded the target molecules a- and y-lycorane, respectively. The purity of the final product was very high with respect to the opposite stereoisomer. Thus <0.2% of /-lycorane was present in a-lycorane and vice versa. 

Glyoxal-sodium bisulfite, 30, 86 Glyoxylic acid, w-butyl ester, 35, 18 ethyl ester, diethyl acetal, 35, 59 Grignard reaction, addition to ethyl sec-butylidenecyanoacetate, 35, 7 allylmagnesium bromide with of,(3-di-bromoethyl ethyl ether, 36, 61 allylmagnesium chloride with a,/3-di-bromoethyl ethyl ether, 36, 63 ethylmagnesium bromide with tin tetrachloride, 36, 86... 

Alternatively, trialkyltinmagnesium halides47, prepared by a Grignard reaction using either alkyl bromides or chlorides, can be hydrolysed to give deuterated or tritiated tin hydrides (equation 43). 

Grignard reaction, addition of methyl-magnesium bromide to thiophos-phoryl chloride, 45,102 Grignard reagents, synthesis and utility of unsolvated, 47, 116 titration of, 48, 48... 

Through known methodology, uridine was transformed into the aldehyde 88 (20) (Figure 14). Grignard reaction with allyl magnesium chloride gave a 7 1 mixture of C-5 Isomers and 90, with the crystalline C-5 (R) Isomer being preponderant. 

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