反应详情

Trans-4-methyl-cyclohexanecarbonyl chloride was prepared by heating to reflux trans-4-methyl-cyclohexanecarboxylic acid (5 g, 0.035 mmol) in thionylchloride (5.0 ml) for 2 h followed by purification of the corresponding acyl chloride under reduced pressure in a Kugel-Rhorr apparatus collecting the fraction distilling at 95° C. yielding 5.1 g of the desired material which was used in the next step without further purification. This acyl chloride (1.5 ml, aprox. 10 mmol) was dissolved along with 5-Bromo-3-isopropylamino-thiophene-2-carboxylic acid methyl ester (2 g, 7.12 mmol) in anhydrous dichloroethane (2 mL) and heated at 80° C. (closed vial) for 12 h. The solvents were evaporated, the resulting crude material was dissolved in methanol and left 30 min. at room temperature, concentrated and purified via flash chromatography on silica gel using a 5% EtOAc 95% hexanes mixture of eluents, in this manner 600 mg (21%) of 5-Bromo-3-[isopropyl-(4-methyl-cyclohexanecarbonyl)-amino]-thiophene-2-carboxylic acid methyl ester the was isolated. 1H NMR(CDCl3, 300 MHz): 6.78 (s, 1H), 4.93 (m, 1H), 3.69 (s, 3H), 2.00-1.20 (m, 8H), 1.14 (d, 3H), 0.93 (d, 3H), 0.81 (d, 3H), 0.72-0.70 (m, 2H).

1. temperatureby heating
2. customfollowed by purification of the corresponding acyl chloride under reduced pressure in a Kugel-Rhorr apparatus
3. customcollecting the fraction
4. distillationdistilling at 95° C.