Sodium hydride acyl halides

Dimethylsulfoxide Acyl and aryl halides, boron compounds, bromomethane, nitrogen dioxide, magnesium perchlorate, periodic acid, silver difluoride, sodium hydride, sulfur trioxide... 

Many acylation reactions of esters using sodium hydride as base appear auto-catalytic, with considerable potential for runaway, since the active base in solution is an alkoxide and the alcohol is a product of reaction [4], A safe form of sodium hydride (as a solid solution in a halide) for large-scale industrial use has been claimed [3],... 

Imidazolines (437) are readily iV-alkylated or X-acylated to form 1-alkyl- (438) or 1-acyl derivatives or 1,3-disubstituted salts (439). Improved alkylations involve pre-generation of the imidazoline anions. With excess alkyl halide the quaternary salt is formed, but suitable 2-substituents allow deprotonation by sodium hydride to give 2-alkylideneimidazolidines (440) (87CB2053). 

Acylation of sugars is generally carried out with acyl chlorides or anhydrides, in pyridine solution, at room temperature. Allylation and benzylation is njost efficiently achieved with he corresponding halides in anhydrous N, Af-dimethylformamide, in the presence of a base, ito generate the alcoholate. Sodium hydride is the most convenient one, but its use may... 

Dichloro-2,2-difluoroethylene, 105 (Diethylamino)sulfur trifluoride, 110 Reduction reactions (see also Deoxygenation, Reductive. . . ) of acetals and ketals Dibromoalane, 237 Diisobutylaluminum hydride, 237 Triethylsilane-Tin(IV) chloride, 237 of acetates and other esters to alkanes Nickel boride, 197 Triphenylsilane, 334 of acyl halides to alcohols Sodium cyanoborohydride-Tin(II) chloride, 280... 

Enolate anions of esters, such as ethyl 3-oxobutanoate or diethyl propanedioate, react with aeyl halides or anhydrides to give acylation products. These reactions are carried out best using sodium hydride instead of sodium ethoxide for production of the enol salt, because then no alcohol is liberated to react with the acyl halide or anhydride ... 

Acidic conditions for hydroxy deprotection can be avoided if benzyl-type ethers ate used as the blocking functions. They can be prepared from the alcohols by alkylation with benzyl halide/sodium hydride in DMSO or benzyl halide/silver(I) oxide in DMF (the silver salt does not cause acyl migration as a side... 

A new decarboxylative route to free radicals, which has proved particularly successful in preparative work, embodies the thermal (or photochemical) decomposition reaction of 1-hy-droxypyridine-2(l/f)-thione esters 23 with tributyltin hydride, /er/-butanethiol, or a similar hydrogen donor.These esters can be easily prepared from acyl halides and the sodium salt of l-hydroxypyridine-2(l//)-thione, or from the carboxylic acid, dicyclohexylcarbodiimide and l-hydroxypyridine-2(l/f)-thione. The intermediate radicals were readily reduced to the corresponding hydrocarbons 24 in efficient chain reactions with organotin hydrides or thiols as reaction partners, and the proportion of rearranged to unrearranged products could be controlled by the choice of hydrogen donor, its concentration and the temperature. This system was sufficiently quantitative and well behaved for use in kinetic studies, and the rate constants of the (S-scission reactions of the listed cyclopropylmethyl species were determined. 

Treatment of the compounds 78 with various alkyl halides in the presence of sodium hydride results in 1-alkylation as with normal Reissert com-pounds. ° Acylation has also been reported under these conditions. Under a variety of conditions, however, 78 does not react with benzaldehyde. Acid hydrolysis of 80 gave tetrahydroquinaldic acid, while acid hydrolysis of the alkylated dihydroisoquinoline-Reissert compounds gave the amino acids 81. By first complexing the alkylated dihydroisoquinoline-Reissert compound with zinc chloride in ether and then hydrolyzing the complex, the nitrile was hydrolyzed to an acid, but the amide group was left intact. The perchlorate salts of dihydroisoquinoline-Reissert compounds have also been prepared, and sodium borohydride reduction proceeds in the same manner as reduction of the Reissert salt to... 

There are two commonly used reducing agents, namely first—sodium horohydride (NaBH ) which reduces exclusively aldehydes, ketones and acyl halides and secondly—lithium aluminium hydride (LiAlH ) which reduces the above compounds as well as compormds belonging to the carboxylic acid family. 

Similarly, 130 reacts with sodium hydride and acyl halides to give 3-acyl-perhydro-l,3,4-oxadiazinon-2-ones 133 (Scheme 18) <2002JOC8871, 2001T9789>. Compounds 134-136 have also been prepared by this method <2004JOC714, 2005TA1047, 2006TA2386>. 

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