Triethylamine chloride

Coumarin. In a 250 ml. round-bottomed flask, provided with a small reflux condenser and a calcium chloride drying tube at the top, place 2 1 g, of salicylaldehyde, 2 0 ml. of anhydrous triethylamine and 5 0 ml. of acetic anhydride, and reflux the mixture gently for 12 hours. Steam distil the mixture from the reaction flask and discard the distillate. Render the residue in the flask basic to litmus with solid sodium bicarbonate, cool, filter the precipitated crude coumarin at the pump and wash it with a little cold water. Acidify the filtrate to Congo red with... 

Alternatively, use the following procedure in which triethylamine replaces potassium acetate as the basic catalyst. Place 2 1 g. (2-0 ml.) of purified benzaldehyde, 2 0 ml. of anhydrous triethylamine and 5 0 ml. of A.R. acetic anhydride in a 200 ml. round-bottomed flask, equipped with a short reflux condenser and a calcium chloride drying tube. Boil the solution gently for 24 hours—heating may be interrupted. Incorporate a steam distillation apparatus in the flask and steam distil until the distillate is no longer cloudy (about 100 ml.) and then collect a further 50 ml. of the distillate di ard the steam distillate. Transfer the residue in the flask to a 400 ml. beaker, add water until the vplume is about 200 ml., then 0 2 g. of decolourising carbon, and boil for a few minutes. Filter the hot solution, and acidify the hot filtrate with 1 1 hydrochlorioiaoid... 

A cousin to this reduction is one using stannous chloride (a.k.a. SnCb, a.k.a. Tin chloride) which is done exactly as the calcium one except that about lOOg of SnCb is used in place of the Mg or Ca and the addition occurs at room temperature and the solution is stirred for one hour rather than 15 minutes. Some very good reductions that operate almost exclusively at room temperature with no pressure and give almost 100% yields are to follow. The only reason Strike did not detail these methods is that some of the chemicals involved are a little less common than Strike is used to but all are available to the public. These alternatives include acetlylacetone and triethylamine [73], propanedithlol and trieth-ylamine [74], triphenylphosphine [75], NaBH4 with phase transfer catalyst [76], H2S and pyridine [77], and palladium hydrox-ide/carbon with hydrazine [78], stannous chloride dihydrate [85]. 

A mixture of 0.10 mol of the acetylenic alcohol, 0.12 mol of triethylamine and 200 ml of dichloromethane (note 1) was cooled to -50°C. Methanesulfinyl chloride (0.12 mol) (for its preparation from CH3SSCH3, (08300)30 and chlorine, see Ref. 73) was added in 10 min at -40 to -50°0. A white precipitate was formed immediately. After the addition the cooling bath was removed and the temperature was allowed to rise to -20°0, then the mixture was vigorously shaken or stirred with 100 ml of water. The lower layer was separated off and the aqueous layer was extracted twice with 10-ml portions of CH2CI2. The combined solutions were dried over magnesium sulfate and concentrated in a water-pump vacuum (note 2). The yields of the products, which are pure enough (usually 96%) for further conversions, are normally almost quantitative. 

In 2-aminothiazole the two N-bonded hydrogens are substituted by the trimethylsilyl group with the reagent trimethylsilyl chloride-triethylamine (Scheme 105) (348). 

Alkoxythiazoles are prepared by heterocyclization (274, 462). The Williamson method using catalytic amounts of KI and cupric oxide is also possible (278. 288, 306). 5-Acetoxy-4-alkenylthiazoles are obtained by treatment of 242 with acetyl chloride and triethylamine or with acetic anhydride and pyridine (450). Similarly, the reaction of diphenylketene with 242 affords 5-acyloxy-4-alkenylthiazoles (243) (Scheme 120) (450). The readiness of these o-acetylations suggests that 4-alkylidene thiazoline-5-one might be in equilibrium with 4-alkenyl-5-hydroxythiazoles (450). 

N -Heterocyclic Sulfanilamides. The parent sulfanilamide is manufactured by the reaction of A/-acetylsulfanilyl chloride with excess concentrated aqueous ammonia, and hydrolysis of the product. Most heterocycHc amines are less reactive, and the condensation with the sulfonyl chloride is usually done in anhydrous media in the presence of an acid-binding agent. Use of anhydrous conditions avoids hydrolytic destmction of the sulfonyl chloride. The solvent and acid-binding functions are commonly filled by pyridine, or by mixtures of pyridine and acetone. Tertiary amines, such as triethylamine, may be substituted for pyridine. The majority of A/ -heterocycHc sulfanilamides are made by simple condensation with A/-acetylsulfanilyl chloride and hydrolysis. 

A variation of this procedure is used for sulfisomidine because of the different character of the amino group in the 4-position of a pyrimidine ring. Two moles of the sulfonyl chloride are condensed with one mole of 4-amino-2,6-dimethy1pyrimidine in the presence of triethylamine. The resulting bis(acetylsulfanilyl) derivative is readily hydrolyzed to the product. The formation of the bis(acetylsulfanilyl) derivative has also been employed for other heterocycHc amines, eg, for synthesis of sulfathiazole and sulfamoxole (44), but the 1 1 reaction is probably preferable. 

Reaction of ethyl chloride with an alcohoHc solution of ammonia yields ethylamine, diethylamine, triethylamine, and tetraethyl ammonium chloride (10,11) (see Amines, lower aliphatic). 

Benzyl chloride undergoes self-condensation relatively easily at high temperatures or in the presence of trace metallic impurities. The risk of decomposition during distillation is reduced by the use of various additives including lactams (43) and amines (44,45). Lime, sodium carbonate, and triethylamine are used as stabilizers during storage and shipment. Other soluble organic compounds that are reported to function as stabilizers in low concentration include DMF (46), arylamines (47), and triphenylphosphine (48). 

Ethylamines. Mono-, di-, and triethylamines, produced by catalytic reaction of ethanol with ammonia (330), are a significant outlet for ethanol. The vapor-phase continuous process takes place at 1.38 MPa (13.6 atm) and 150—220°C over a nickel catalyst supported on alumina, siUca, or sihca—alumina. In this reductive amination under a hydrogen atmosphere, the ratio of the mono-, di-, and triethylamine product can be controlled by recycling the unwanted products. Other catalysts used include phosphoric acid and derivatives, copper and iron chlorides, sulfates, and oxides in the presence of acids or alkaline salts (331). Piperidine can be ethylated with ethanol in the presence of Raney nickel catalyst at 200°C and 10.3 MPa (102 atm), to give W-ethylpiperidine [766-09-6] (332). 

Pyrrole and alkylpyrroles can be acylated by heating with acid anhydrides at temperatures above 100 °C. Pyrrole itself gives a mixture of 2-acetyl- and 2,5-diacetyl-pyrrole on heating with acetic anhydride at 150-200 °C. iV-Acylpyrroles are obtained by reaction of the alkali-metal salts of pyrrole with an acyl halide. AC-Acetylimidazole efficiently acetylates pyrrole on nitrogen (65CI(L)1426). Pyrrole-2-carbaldehyde is acetylated on nitrogen in 80% yield by reaction with acetic anhydride in methylene chloride and in the presence of triethylamine and 4-dimethylaminopyridine (80CB2036). 

Substituted imidazoles can be acylated at the 2-position by acid chlorides in the presence of triethylamine. This reaction proceeds by proton loss on the (V-acylated intermediate (241). An analogous reaction with phenyl isocyanate gives (242), probably via a similar mechanism. Benzimidazoles react similarly, but pyrazoles do not (80AHC(27)24l) cf. Section 4.02.1.4.6). 

Of particular interest is the reaction of 5,5-disubstituted sulfur diimides (188) with oxalyl chloride in dilute solution in the presence of triethylamine. The l,2,5-thiadiazole-3,5-dione (189) was formed in almost quantitative yield (72LA(759)107). 

In addition to (461), Dorn has described the imine (463) isolated from 5-amino-l-methylpyrazole and arenesulfonyl chloride (80CHE1). Upon heating, or in the presence of triethylamine, it undergoes rearrangement to the more stable 5-bis(arylsul-fonamido)pyrazoles (464). 5-Iminopyrazolines (461) react with acyl chlorides at the exocyclic nitrogen atom to afford amidopyrazolium salts (B-76MI40402). 

Treatment of (537) with acid chloride (538) in the presence of triethylamine produced isoxazolidine (539) in 45% yield (80IZV1694). 

The interaction of acid chlorides (167 X = Cl) with imines in the presence of bases such as triethylamine may involve prior formation of a ketene followed by cycloaddition to the imine, but in many cases it is considered to involve interaction of the imine with the acid chloride to give an immonium ion (168). This is then cyclized by deprotonation under the influence of the base. Clearly, the distinction between these routes is a rather fine one and the mechanism involved in a particular case may well depend on the reactants and the timing of mixing. Particularly important acid chlorides are azidoacetyl chloride and phthalimidoacetyl chloride, which provide access to /3-lactams with a nitrogen substituent in the 3-position as found in the penicillins and cephalosporins. 

The dibenzosuberyl ether is prepared from an alcohol and the suberyl chloride in the presence of triethylamine (CH2CI2, 20°, 3 h, 75% yield). It is cleaved by acidic hydrolysis (1 N HCl/dioxane, 20°, 6 h, 80% yield). This group has also been used to protect amines, thiols, and carboxylic acids. The alcohol derivative can be cleaved in the presence of a dibenzosuberylamine. ... 

Tosylates are generally formed from an amine and tosyl chloride in an inert solvent such as CH2CI2 with an acid scavenger such as pyridine or triethylamine. 

A. l-THmethyleilyloxyayalopentsne. A 1-L, two-necked, round-bottomed flask is equipped with a mechanical stirrer and a reflux condenser having a drying tube (calcium chloride). The flask is charged with 200 mL of dimethylformamide (Note 1), 45 g (0.54 mol) of cyclopentanone (Note 2), 65.5 g (0.6 mol) of chlorotrimethylsilane (Note 2) and 185 mL (1.33 mol) of triethylamine (Note 1), and the mixture is refluxed for 17 hr (Note 3). The mixture is cooled, diluted with 350 mL of pentane, and washed four times with 200-mL portions of cold saturated aqueous sodium hydrogen carbonate. The... 

A 600-mL, three-necked, round-bottomed flask 1s equipped with a mechanical stirrer, a short gas inlet tube, and an efficient reflux condenser fitted with a potassium hydroxide drying tube. The flask is charged with 13.4 g (0.05 mol) of 3-ben2y1-5-(2-hydroxyethyl)-4-methyl-l,3-th1azol1um chloride (Note 11, 72.1 g (1.0 mol) of butyraldehyde (Note 2). 30.3 g (0.3 mol) of triethylamine (Note 2), and 300 raL of absolute ethanol. A slow stream of nitrogen (Note 3) is begun, and the mixture is stirred and heated In an oil bath at 80°C. After 1.5 hr the reaction mixture is cooled to room temperature and concentrated by rotary evaporation. The residual yellow liquid Is poured Into 500 mL of water contained 1n a separatory funnel, and the flask is rinsed with 150 mL of dichloromethane which is then used to extract the aqueous mixture. The aqueous layer is extracted with a second 150-mL portion of... 

With more strongly basic tertiary amines such as triethylamine, another mechanism can come into play. It has been found that wften methanol deuterated on oxygen reacts with acyl chlorides in the presence of triethylamine, some deuterium is found a to the carbonyl group in the ester... 

---