* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Reference:
[1] Journal of the American Chemical Society, 1923, vol. 45, p. 2395
[2] Gazzetta Chimica Italiana, 1922, vol. 52 I, p. 31
[3] Gazzetta Chimica Italiana, 1922, vol. 52 I, p. 31
2
[ 75-15-0 ]
[ 95-53-4 ]
[ 2268-77-1 ]
Reference:
[1] Journal of the American Chemical Society, 1923, vol. 45, p. 2395
2-Mercapto -4-methyl-benzothiazole (340) The title compound was prepared using the method of example 239, starting with 2-bromo-4-methyl-phenylamine (Acros) (27.9 g), O-ethylxanthic acid, potassium salt (Lancaster, 54 g) in DMF (250 mL). The mercaptobenzothiazole 340 was obtained as an pale brown solid (27 g). Recrystalization from CHCl3 gave pinkish white crystals (20 g). 1H NMR (DMSO-d6) delta 7.499 (br s, 1H), 7.223 (d, J=8 Hz, 1H), 7.198 (d, J=8 Hz, 1H), 2.342 (s, 3H).
3
[ 13001-46-2 ]
[ 87-63-8 ]
[ 2268-77-1 ]
Yield
Reaction Conditions
Operation in experiment
With potassium carbonate; In N-methyl-acetamide; water;
EXAMPLE 4 A solution of 250 g of potassium isobutyl xanthate (about 90% pure) in 400 ml of dimethylformamide is added dropwise to a mixture of 141.5 g of 2-chloro-6-methylaniline and 276 g of potassium carbonate in 1 liter of dimethylformamide at 150 C. in the course of one hour, under a nitrogen atmosphere. The reaction mixture is stirred for about a further 26 hours, whilst cooling intensively. The batch is cooled, freed from salt and then concentrated to dryness. The residue is taken up in 400 ml of water and the mixture is acidified. The 4-methyl-2-mercaptobenzothiazole which precipitates is filtered off, washed with water and dried. 172 g (95% of theory) of 4-methyl-2-mercaptobenzothiazole of melting point 188-190 C. are obtained.
With carbon disulfide; sodium hydroxide; hydrogen sulfide; In water;
EXAMPLE I The following run (Run 1) illustrates the prior art process of preparing 2-mercapto-4-methylbenzothiazole from o-toluidine, carbon disulfide, and sulfur. Into a 500 ml reactor were charged o-toluidine (27 g), sulfur (8g), and carbon disulfide (22 g). Seventy minutes of electrically heating the system was required to elevate the temperature to 275C (240 psig original pressure at 275C). After 21/2 hours at 275C (the pressure leveled out at 470 psig in 90 minutes) the heat source was removed and the reactor was cooled. The reaction mixture was mixed with 200 g water containing 16 g sodium hydroxide. Tar-like residue (18.5 g) was removed by decantation. Acidification of decantate with hydrochloric acid and filtration of the resulting mixture gave 21 g (46 percent yield) of crude 2-mercapto-4-methylbenzothiazole (m.p. 161-173C).
With copper(l) iodide; tetrabutylammomium bromide; sodium carbonate; In water; at 100℃; for 24h;Sealed tube; Green chemistry;
General procedure: To a 10 mL sealed tube with a stir bar were added CuI (0.05 mmol), Aryl iodides (0.6 mmol), 2-mercaptobenzothiazoles (0.5 mmol), and Na2CO3 (1.0 mmol), H2O (2 mL) and the mixture was stirred for 24 h at 100 C. The mixture was then cooled to rt and extracted with EtOAc (3 10 mL). The organic layers were combined,washed with sat. brine (2 10 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The crude product was purified by columnchromatography.
With sodium hydrogen sulfide; In water; at 80℃; for 9h;Green chemistry;
To the reaction flask was added 11 lmg (0.40 mmol) of 6,6'-dimethyl-2,2'-dithiodiphenamine and 11.2 mg (0.2 mmol) of NaHS followed by 2.5 mL of H20 As a reaction solvent, and then injected into 97yL (l · 6mmol) of carbon disulfide, the reaction was stirred at 80 C for 9 hours after plate chromatography detected disulfide raw material was completely reacted, cooled to room temperature, extracted with ethyl acetate, The solvent was removed under reduced pressure on a rotary evaporator to give the crude product. The crude product was eluted with methylene chloride and eluted with a gradient. The residue was purified by column chromatography (200300 mesh silica gel) to give 124.4 mg of 4-methyl-2-mercaptobenzothiazole as white powder with a purity of more than 99% Isolated yield 85.8%, mp 191-193 C
With 1.3-propanedithiol; dimethyl sulfoxide; potassium hydroxide; at 130℃; for 12h;Inert atmosphere;
General procedure: To a solution of benzothiazoles or benzoxazoles (1, 1 mmol) in DMSO (3 mL), was added KOH (280 mg, 5 equiv) and 1,3-propanedithiol (207 muL, 2 mmol). The reaction mixture was heated under argon at 130 C for 12 h. After cooling to room temperature, water (10 mL) was added. The pH of the reaction mixture was adjusted to 3-4 using 5% HCl. The resulting mixture was extracted with ethyl acetate (15 mL ×2). The organic layer was washed with water and brine, dried over anhydrous MgSO4 and concentrated using rotary evaporator. The crude product was purified by silica gel column chromatography using ethyl acetate/n-hexane as eluent to afford the corresponding heteroaryl thiols 3.
In N,N-dimethyl acetamide; at 150℃; for 0.0833333h;Microwave irradiation;
General procedure: In a 20mL microwave reaction vial (Biotage), a mixture of substituted 2-halogeno-aniline (1 equiv, 500 mg), O-isopropylxanthic acid potassium salt (PIX) (2 equiv), and DMAC (8 mL) was added. The vial was irradiated at 150 C for 5 min in a Biotage microwave reactor. The mixture was cooled to room temperature. Then it was poured into cold H2O and adjusted to pH 3 by HCl 1N. The precipitate was filtered and washed (5 times) with H2O to afford products without additional purification.
N-(3-hydroxy-4-methoxybenzyl)-2-((4-methylbenzo[d]thiazol-2-yl)thio)-N-(3,4,5-trimethoxyphenyl)acetamide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
42%
With potassium carbonate; In acetonitrile; at 80℃; for 6h;
General procedure: A solution of compounds E1-E11 (0.5 mmol, 1.0 eq), substituted benzothiazoles (0.6 mmol, 1.2 eq) and K2CO3 (0.75 mmol, 1.5 eq) were added into acetonitrile (10 ml) at 80 C for 6 h. Upon completion, organic phase was collected to obtain crude products and then were purified with column chromatography to give compounds F1-F14.
2-((difluoromethyl)thio)-4-methylbenzo[d]thiazole[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
89%
With water; sodium hydroxide; In acetonitrile; at 20℃; for 0.166667h;
General procedure: A mixture of 8 or 10 (1 mmol), NaOH (11 mmol, 0.44 g) was dissolved in CH3CN (CH3CN/H2O 10/1, V/V, 11 mL) in an oven dried 50 mL round bottom flask containing a stir bar. Iododifluoroacetophenone (2) (2 mmol, 0.56 g), was added to the reaction mixture and stirred at room temperature for about 10 min. After the reaction was completed as indicated by TLC the reaction mixture was removed under reduced pressure. And then, the reaction mixture was diluted with water (50 mL) and extracted with EtOAc (25 mL x 3), followed by brine (50 mL). The organic extract was dried over NaSO4, filtered and evaporated under reduced pressure. The crude product was further purified by silica gel column chromatography using (pet ether/EtOAc) to furnish the S- and O-CF2H derivatives 9a-9h and 11a-11h.
With N-chloro-succinimide; In acetonitrile; at 20℃; for 0.5h;
In an air atmosphere at room temperature, 0.5 mmol (90 mg) of p-<strong>[2268-77-1]4-methyl-2-mercaptobenzothiazole</strong> and 1.5 mmol (200 mg) of N-chlorosuccinimide were put into a round-bottomed flask, and about 2 mL of solvent acetonitrile was added. , stirred, and reacted at room temperature for half an hour. After the reaction was completed, the reaction solution was transferred to a 250 mL separatory funnel, extracted with ethyl acetate (30 mL × 3), and the upper organic phases were combined, dried, filtered, and distilled to obtain crude The product was finally separated by column chromatography to obtain the product, the ratio of passing through the column was PE:EA=90:1, and the product yield was 79% (77 mg). The product is a colorless oily liquid.