Chloroacetaldehyde 40% aqueous

Synonyms/Trade Names Chloroacetaldehyde (40% aqueous solution), 2-Chloroacetaldehyde, 2-Chloroethanal... 

Aj Preparation of 3-Chloromethyl-6-Chloro-7-Sulfamyl-3,4-Dihydro-Benzothiadizine-1,1-Dioxide—Jo 8 ml of 40-50% chloroacetaldehyde aqueous solution and 7 ml of dimethyl-formamide are added 10 grams of 2,4-disulfamvl-5-chloroaniline. The mixture is heated on a steam bath for 2 hours after which it Is concentrated at reduced pressure. The residue Is triturated with water. The solid material is recrystallized from methanol-ether after-treatment with activated carbon to give 7.2 grams of product, MP 229°-230°C. 

Another difficulty in this reaction lies in the preparation of pure chloroacetaldehyde. The low yield observed is due to simultaneous formation of by-products (polyhalogenation). So vinylchloride was used as a starting material for this synthesis (449). A simpler method is to react chlorine with vinylchloride in aqueous solution and then to dehydrate the semihydrated chloroacetaldehyde by distillation through a column of calcium chloride heated to 70 to 90 C (451). 

The results initially obtained were due to the formation in both aqueous and alcoholic solution of resinous by-products. This formation results from the decomposition of the ammonium dithiocarbamate, or from the self-condensation of chloroacetaldehyde or the formation of intermediate products. 

Vinyl chloride can be completely oxidized to CO2 and HCl using potassium permanganate [7722-64-7] in an aqueous solution at pH 10. This reaction can be used for wastewater purification, as can ozonolysis, peroxide oxidation, and uv irradiation (42). The aqueous phase oxidation of vinyl chloride with chlorine yields chloroacetaldehyde (43). 

A cross-coupling reaction of aldehydes with a-diketones proceeded in the presence of water to give the corresponding adducts in moderate to good yield. It is possible to use the substrates such as phenyl-glyoxal monohydrate, aqueous methylglyoxal, formalin, and aqueous a-chloroacetaldehyde for this reaction.330... 

Reaction of the 2,4-diaminopyrimidine 278 with chloroacetaldehyde 279 in the presence of aqueous sodium acetate generates the tricyclic system 280 in low yield (Equation 77) <2004T943>. 

Sc(OTf)3 is effective in aldol reactions in aqueous media (water-THF, Scheme 15).49 Direct treatment of aqueous solutions of water-soluble formaldehyde and chloroacetaldehyde with silyl enol ethers affords the corresponding aldol adducts in good yields. Water-sensitive silicon enolates can be used in aqueous solutions in the presence of a catalytic amount of Sc(OTf)3. 

Craig and co-workers247 reported the synthesis of l-aza-2,4,10-trithiaada-mantane (227) as a by-product in the reaction of ammonium dithiocarbamate with an aqueous solution of chloroacetaldehyde. The same compound is reported to be obtained by the reaction of mercaptoacetaldehyde with ammonia248 and then by the reaction of tri(2,2-bis(ethoxy)ethyl]amine (228) with hydrogen sulfide in the presence of hydrobromic acid.249 The... 

The chloromethylpyrimido[5,4-( ]-l,2,4-triazine 86 is an extremely versatile starting material (see Section 10.20.7.2, Equation 12) and was synthesized from the commercially available thiol 151 as shown in Scheme 25. Thus, 6 -methylation of compound 151 gave the sulfide 152, which was nitrosated to allow access to the nitroso-thiomethyl derivative 153. Nucleophilic substitution of the thiomethyl group by hydrazine gave the cyclization precursor 154, which underwent cyclization with chloroacetaldehyde diethyl acetal under acidic conditions to give the chloro-methylpyrimido[5,4-( ]-l,2,4-triazine 86 after workup with aqueous ammonia <2003BML2895>. 

By analogy with the preparation of furo[3,2-c]pyridones (Scheme 14), treatment of 4-hydroxy-6-methylpyran-2-one (66) with chloroacetaldehyde in basic aqueous medium... 

In both processes the aqueous crude aldehyde is concentrated and byproducts are removed in a two-step distillation. Both processes give 94% yields of aldehyde, along with small amounts of 2-chloroethanol, ethyl chloride, acetic acid, chloroacetaldehydes and acetaldehyde condensation products. The Wack-er-Hoechst process currently accounts for 85% of the worldwide production capacity for acetaldehyde. 

CjHjOCHjCHjBt, is readily replaced by the cyano group from sodium cyanide (58%). It is interesting to note that aqueous potassium cyanide effects a cleavage of the carbon-oxygen bond in a,/3-dichloroethyl ether, giving the cyanohydrin of chloroacetaldehyde, CHjClCHOHCN (40%). ... 

Reaction of chloroacetaldehyde with adenine, adenosine as well as its nucleotides (see Section 7.1.1.3.7.) results in the formation of the so-called etheno compounds eAde, eA, eAMP, etc. These fused purine derivatives exhibit intensive fluorescence ethenoadenosine, for example, shows an emission maximum at 415 nm (excitation 310 nm) in aqueous solution (pH 7) with a quantum yield of 0.56 (life time 20 nsec).All adenine derivatives have similar fluorescence properties the nucleotide analogs show considerable substrate activities with different kinases. 

The importance of aqueous reactions is now generally recognized, and development of carbon-carbon bond-forming reactions that can be performed in aqueous media is now one of the most challenging topics in organic synthesis [59]. It has been found that Sc(OTf)3 was effective in aldol reactions of silyl enolates with aldehydes in aqueous media (water-THF Eq. 16) [4]. Reaction between aromatic and aliphatic aldehydes such as benzaldehyde and 3-phenylpropionaldehyde and silyl enolates have been performed successfully in aqueous solvents. In addition, direct treatment of aqueous solutions of water-soluble formaldehyde and chloroacetaldehyde with silyl enolates affords the corresponding aldol adducts in good yields. Water-sensitive silyl enolates could be used in aqueous solutions with Sc(OTf)3 as catalyst. 

Mannich-type reactions of aldehydes, amines, and vinyl ethers proceeded smoothly in the presence of a catalytic amount of Sc(OTf)3 in aqueous media (Eq. 20) [69]. Commercially available aqueous solutions of formaldehyde and chloroacetaldehyde were used directly and the corresponding /3-amino ketones were obtained in good yields. Phenylglyoxal monohydrate, methyl glyoxylate, an aliphatic aldehyde, and an a,/3-unsaturated aldehyde also worked well to give the corresponding /3-amino esters in high yields. 

The use of Ln(OTf)3 in the activation of aldehydes other than formaldehyde was also investigated [18], Several examples of the present aldol reaction of silyl enol ethers with aldehydes are listed in Table 14-1. In every case, the aldol adducts were obtained in high yields in the presence of a catalytic amount of Yb(OTf)3, Gd(OTf)3, or Lu(OTf)3 in aqueous media. Diastereoselectivities were generally good to moderate. One feature in the present reaction is that water-soluble aldehydes, for instance, acetaldehyde, acrolein, and chloroacetaldehyde, can be reacted with silyl enol ethers to afford the corresponding cross aldol adducts in high yields (entries 5-7). Some of these aldehydes are commercially supplied as water solutions and are appropriate for direct use. Phenylglyoxal monohydrate also worked well (entry 8). It is known that water often interferes with the aldol reactions of aldehydes with metal enolates and that, in the cases where such water... 

Sc(OTf)3 can behave as a Lewis acid catalyst even in aqueous media. Sc(OTf)3 was stable in water and was effective in the aldol reactions of silyl enolates with aldehydes in aqueous media. The reactions of usual aromatic and aliphatic aldehydes such as benzaldehyde and 3-phenylpropionaldehyde with silyl enolates were carried out in both aqueous and organic solvents, and water-soluble formaldehyde and chloroacetaldehyde were directly treated as water solutions with silyl enolates to afford the aldol adducts in good yields. Moreover, the catalyst could be recovered almost quantitatively from the aqueous layer after the reaction was completed. The recovered catalyst was also effective in the second reaction, and the yield of the second run was comparable to that of the first run (Eq. 2). 

Acetaldehyde derivatives chlorinated at the -position are interesting intermediates. Chloroacetaldehyde, CH2C1—CHO, b.p. 85-85.5°/748 mm, can be obtained by chlorinating acetaldehyde in aqueous HC1 at 18-20° 619 or by chlorinating anhydrous acetaldehyde below io° 140a 620 in the latter case there must be efficient cooling, particularly at the start, to avoid inflammation due to reaction of chlorine with the acetaldehyde vapor only a small amount of acetaldehyde is used at first, and the remainder, cooled in Dry Ice, is added later in portions the rate of chlorination (to d 1.31) is controlled by the rate at which the heat of reaction can be removed. 

Numerous examples of such reactions (equation 34) have been reported in earlier reviews ". In the well-known standard synthesis of alkoxyalkynes f reaction of acetals of chloroacetaldehyde 52 with sodium amide in liquid ammonia has been used to generate sodium alkoxyacetylide 54. Recently, this elimination procedure has been further improved by using lithium diethylamide in THE solution (equation 35)". In this work" in situ generated lithium alkoxyacetylide 56 was subsequently converted to either ethoxyacetylene 57 by quenching with saturated aqueous sodium diioride, or ethoxyethynyl carbinols 58 by subsequent reaction with ketones or aldehydes. 

Chloroacetaldehyde is a highly toxic and corrosive compound that can injure the eyes, skin, and respiratory system. Exposure to its vapor at high concentrations can produce severe irritation and impair vision. At low concentrations, the vapor can cause irritation and sore eyelids. Brief contact with 40% aqueous solution can result in skin bum and destruction of tissues. A 0.5% dilute solution can still be irritating on skin. 

Heating 2-amino-4-chlorobenzenesulfonamide with chloroacetaldehyde in the presence of NH4CI in aqueous DMF results in a high yield of the corresponding 3-chloromethyl-3,4-dihydro-2//-l-thia-2,4-diazine 1,1-dioxide 223 (Equation 51) <2005BMC1393>. 

Sc(OTf)3 is effective in the aldol-type reaction of silyl enolates with aldehydes in aqueous media (H2O-THF) without any significant decomposition of the water-sensitive silyl enolates. Thus, aldehydes available in aqueous-solution such as formaldehyde and chloroacetaldehyde can be directly used to afford the corresponding aldol adduct in high yield (eq 3). ... 

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