Name | METHYL 2-BROMOTHIAZOLE-4-CARBOXYLATE |
Synonyms | METHYL 2-BROMOTHIAZOLE-4-CARBOXYLATE 2-Bromo-4-(methoxycarbonyl)-1,3-thiazole Methyl 2-Bromothiazole-4-Carboxylate sky Methyl 2-bromo-1,3-thiazole-4-carboxylate 2-BROMOTHIAZOLE-4-CARBOXYLIC ACID METHYL ESTER 4-Thiazolecarboxylic acid, 2-broMo-, Methyl ester |
CAS | 170235-26-4 |
InChI | InChI=1/C5H4BrNO2S/c1-9-4(8)3-2-10-5(6)7-3/h2H,1H3 |
InChIKey | YOWKNNKTQWCYNC-UHFFFAOYSA-N |
Molecular Formula | C5H4BrNO2S |
Molar Mass | 222.06 |
Density | 1.759±0.06 g/cm3(Predicted) |
Melting Point | 118-122 |
Boling Point | 263.3±13.0 °C(Predicted) |
Flash Point | 113°C |
Water Solubility | Slightly soluble in water. |
Vapor Presure | 0.0104mmHg at 25°C |
Appearance | Solid |
pKa | -1?+-.0.10(Predicted) |
Storage Condition | Keep in dark place,Sealed in dry,Room Temperature |
Refractive Index | 1.583 |
MDL | MFCD06659908 |
Physical and Chemical Properties | Storage Conditions: Keep Cold |
Hazard Symbols | Xi - Irritant |
Safety Description | 24/25 - Avoid contact with skin and eyes. |
HS Code | 29339900 |
Hazard Note | Irritant/Keep Cold |
application | methyl 2-bromothiazole -4-carboxylate is a pharmaceutical intermediate and intermediate It is mainly used in the laboratory research and development process and the chemical and pharmaceutical research and development process. It can be prepared in three steps by using ethyl bromopyruvate and thiourea as starting materials. |
Preparation | Step 1. Preparation of Ethyl 2-Amino-4-thiazolate Ethyl Bromopyruvate (90%,10.0 mL, about 70 mmol) and thiourea (5.5g,71.5 mmol) are combined and slowly heated to 100 degrees Celsius (oil bath), keep at this temperature for 20 minutes. The reaction mixture becomes uniform at 70°C, and then a rapid exothermic reaction is observed (the temperature must be carefully controlled to avoid violent reactions). After cooling and drying under high vacuum, 12.8g light brown solid ethyl 2-amino-4-thiazoloformate was obtained, which was pure enough for direct use in the next step. Pure samples of colorless solids were obtained by recrystallization from ethyl acetate. TLC:Rf = 0.08 (ethyl acetate/cyclohexane = 1 ∶ 2). Step 2. Preparation of Ethyl 2-Bromo-4-thiazolarboxylate The sulfuric acid (9 M,150 ml) mixture of ethyl 2-amino-4-thiazolarboxylate (12.8g, about 70 mmol),CuSO4(34.2g,215 mmol) and NaBr(29.5g,285 mmol) is cooled in an ice salt bath at -5 to 0 degrees Celsius (internal temperature), A solution of NaNO2(5.9g,85 mmol) in H2O(100 ml) (precooled to 0 degrees Celsius) was added dropwise within 60 minutes. The internal temperature is kept below 0 ℃ during the addition process. After stirring at 0°C for 1 hour, the reaction mixture was gradually warmed to room temperature within 1 hour, and stirred for another 1 hour. The mixture was then diluted with water (200mL) and extracted with ether (5 × 200mL). The combined ether extract was dried with sodium sulfate and concentrated. The crude product ethyl 2-bromo-4-thiazole carboxylate (12.7g, colorless powder) is directly used for the next step without purification. The samples were analyzed by column chromatography purification. TLC:Rf = 0.68 (ethyl acetate/cyclohexane = 1 ∶ 2). Step 3. the preparation of 2-bromothiazole-4-carboxylic acid methyl ester 2-bromo-4-thiazole carboxylic acid ethyl ester (12.7g) was dissolved in methanol (150mL) and concentrated sulfuric acid (1mL) was added. Heat the mixture to reflux for 12 hours (TLC control). The solvent was evaporated, the residue was diluted with H2O(150mL), neutralized with saturated sodium bicarbonate solution, and extracted with dichloromethane (4 × 100mL). The combined extracts were dried with sodium sulfate and concentrated. By column chromatography purification (silica gel, 80g, ethyl acetate/cyclohexane = 1 ∶ 15), 6.5g of 2-bromothiazol-4-carboxylic acid methyl ester (29.4mmol,49%, three-step method) was obtained as a colorless solid. TLC:Rf = 0.55 (ethyl acetate/cyclohexane = 1 ∶ 2). |