Trimethylacetyl Chloride

Alternate Names pivaloyl chloride 2,2-dimethylpropanoyl chloride. 

Form Supplied in colorless liquid widely available. 

Handling, Storage, and Precautions flammable can cause severe burns and is irritating to the eyes and respiratory system toxic by contact with the skin, by inhalation, and if swallowed. It should be used in a fume hood. During use, avoid sources of ignition and any contact. Avoid exposure to moisture.  

Ketone Synthesis. Carboxylic acids can be converted to ketones by first forming the mixed anhydride with trimethylacetyl chloride and then treating it with a Grignard reagent (eq 2) In addition to trimethylacetyl chloride, ort/jo-substituted benzoyl chlorides such as o-anisoyl chloride can be used to form the mixed anhydride. Yields were found to be slightly higher than when trimethylacetyl chloride was used.  

The carboxylic acid (1) has been converted to the ketone (2) via the mixed anhydride with trimethylacetyl chloride (eq 3).  

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Pivaloyl chloride (trimethylacetyl chloride) [3282-30-2] M 120.6, b 57.6"/150mm, 70.5-71/250mm, 104"/754mm, 104-105"/atm, 105-108"/atm, d 1.003, n p 1.4142. First check the IR to see if OH hands are present. If absent, or present in small amounts, then redistil under moderate vac. If present in large amounts then treat with oxalyl chloride or thionyl chloride and reflux for 2-3h, evap and distil residue. Strongly LACHRYMATORY - work in a fumecupboard. Store in sealed ampoules under N2. [Traynham and Battiste J Org Chem 22 1551 1957, Grignard reactns Whitmore et al. J Am Chem Soc 63 647 1941.]... 

Thionyl chloride Thiophosgene Titanium tetrachloride Trichloromethyl perchlorate Triformoxime trinitrate Trimethylacetyl chloride Trimethylene glycol diperchlorate Trimethylol nitromethane trinitrate... 

To a solution of (extracted with three 10-mL portions of ethyl acetate. The combined organic extracts are washed with 20 mL of brine, dried over MgS04, filtered, and concentrated under reduced pressure. The residue is purified by chromatography on silica gel (elution with 1% EtOAc/hexanes) to afford 0.129 g (87%) of ester 6 (Note 18). 

Pyridine was freshly distilled from calcium hydride and stored under nitrogen over potassium hydroxide. Trimethylacetyl chloride (99%) was obtained from Aldrich Chemical Company and used as received. 

All reagents were purchased from Aldrich Chemical Company (except for trimethylacetyl chloride, which the checkers obtained from Acros) and were used without further purification. The checkers used a low temperature alcohol thermometer in place of a Teflon-coated themocouple. The third neck of the flask was left open to the atmosphere. 

A syringe pump was used for the addition of acid chloride in order to achieve a steady flow rate. The tip of the syringe needle (gauge 20) was submerged in the reaction mixture. Dropwise addition of trimethylacetyl chloride at 0-5°C resulted in the immediate formation of a precipitate. 

Trimethylacetamide, d678 Trimethylacetic acid, d679 Trimethylacetic anhydride, d680 Trimethylacetyl chloride, d681... 

Glutaryl dichloride undergoes reduction at mercury to give 5-chlorovalerolactone and valerolactone a polymeric solid, possibly X[(CH2)3CHCl-0-C=0] (CH2)3X (whereX = CHO or CO2H), is additionally produced [73]. Heptanoyl chloride [71], trimethylacetyl chloride [74], and cyclo-hexanecarbonyl chloride [75] can be reduced at carbon or mercury cathodes to form the corresponding aldehydes in addition, the anhydride (and sometimes... 

High yields (76-81%) of alcohols are also obtained by adding solutions of acyl chlorides in anhydrous dioxane or diethyl carbitol to a suspension of sodium borohydride in dioxane and brief heating of the mixtures on the steam bath [751], by stirring solutions of acyl chlorides in ether for 2-4 hours at room temperature with aluminum oxide (activity I) impregnated with a 50% aqueous solution of sodium borohydride (Alox) (yields 80-90%) [1014], by refluxing acyl chlorides with ether solutions of sodium trimethoxyborohydride [99], or by treatment of acyl chlorides in dichloromethane solutions with tetrabutylammonium borohydride at —78° [771]. A 94% yield of neopentyl alcohol was achieved by the reaction of trimethylacetyl chloride with tert-butylmagnesium chloride [324]. 

Trimethylacetic anhydride, d599 Trimethylacetyl chloride, d600... 

Trimethylacetic formic anhydride, (CHr)iCC02CH0 (1). The anhydridesis prepared in high yield by reaction of trimethylacetyl chloride and sodium formate (1.05 equiv.) in the presence of 18-crown-6 (10 mol %) at 0° the yield of slightly impure material is 95-98%. The material can be stored in a freezer for several months. 

Trimethylacetyl chloride was purchased from the Aldrich Chemical Co. The purity, determined by nmr, was at least 99%. If it is less pure than this, the material should be distilled under nitrogen. 

The Step 9 product was dissolved in 4 ml CH2C12 and treated with trimethylacetyl chloride (2.5 mmol), then stirred 2 hours. The mixture was neutralized with saturated NaHC03 solution, extracted three times with 10 ml CH2C12, dried, and concentrated onto silica gel. The product was purified by flash chromatography using 50% EtOAc/1% triethylamine/hexane and 690 mg product isolated as a white foam. The addition of 1.2 ml 1M HC1 dissolved in 5 ml diethyl ether provided the final product. 

Trimethylacetyl chloride (0.065 mol) was added to 4-methyl-2-pentenoic acid (0.06 mol) and triethylamine (0.187 mol) dissolved in 200 ml THF at —20°C. After 1 hour the mixture was treated with LiCl (0.55 mol) and (R)-(-)-4-phenyl-2-oxazolidinone (0.05 mol) and a thick suspension formed, which was stirred 20 hours at ambient temperature. The suspension was filtered and the filtrate concentrated. The residue was recrystallized using hexane/EtOAc, 5 1, and the product isolated in 68% yield as a white solid. 

Ketene thioacetals. The enolate (1) of 2-carbomethoxy-1,3-dithiane does not normally react with aldehydes or ketones, but a 1 1 mixture of trimethylacetyl chloride and an aldehyde reacts in THF to form the pivaloxy ester 2. This product undergoes dccar-boalkoxylation (9, 283 11, 301) when heated in ilry DMF with excess Li I to form ketene thioacetals (3). 

Grignard reagents have been used directly in mono-and diketone formation. More recently, it has been found that a catalytic quantity of cuprous chloride greatly increases the yields." An example is the formation of hexamethylacetone in 70-80% yield from t-butylmagnesium chloride and trimethylacetyl chloride. Diketones have... 

Methods of IV-Acylation. Lithiated oxazolidinones add to acid chlorides (eq 7) and mixed anhydrides (eq 8) in high yields to form the derived Af-acyl imides. In the latter case the anhydride may be formed in situ with Trimethylacetyl Chloride, and then condensed with the lithiated oxazoiidinone selectively at the less hindered carbonyl moiety. 

Trimethylacetyl chloride (pivaloyl chloride) has also found widespread use for mixed anhydride formation. This reagent is frequently superior to isobutyl chloroformate where condensation reactions involve highly hindered amines. Mixed anhydrides derived from pivaloyl chloride may be generated in the same manner as from isobutyl chloroformate. 

TrimethyI-3-aceloxy-l-pyrazoline, 543 Trimethylacetyl chloride, 591, 1229 Trimethylamine, 410 Trimethylamine-borane, 16, 1229-1230 Trimethylamine oxide, 1230-1231 Trimethylaminoacetohydrazide chloride,... 

Oxadiazon can be obtained by the following synthesis route pivaloyl chloride (trimethylacetyl chloride) is condensed with 2,4-dichloro-5-isopropoxyphenyl-... 

Dimethylpropanoyl chloride EINECS 221-921-6 Pivaloyl chloride Propanoyl chloride. 2,2-dimethyl- Trimethylacetyl chloride ... 

A similar cyclization procedure uses C-acylnitrilium ions for the synthesis of heterocyclic compounds.55 A typical example treated isonitrile 107 with trimethylacetyl chloride to give 108.56 Subsequent treatment with Ag03SCF3 (silver trifluoromethanesulfonate) gave an intermediate C-acylnitrilium ion (109), which cyclized... 

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