Butyl 6-isocyanatohexanoate → HCID 19848120, compound

Participants

Reaction Steps

10.0 g of 2,5-bis-(isopropoxycarbonyl)-3-methyl-4-hydroxythiophene, 20 ml of anhydrous acetonitrile, 15 g of butoxycarbonylpentyl isocyanate (b.p. 149°-151°/ 13 millibar) and 100 mg of triethylene diamine are maintained at 100° C. for 18 hours. The mixture is diluted with 20 ml of acetonitrile. To remove the excess butoxycarbonylpentyl isocyanate, the reaction mixture is shaken three times with 50 ml of ligroin in each case. The acetonitrile phase is evaporated in vacuo. The evaporation residue is dried at 100° C./0.1 mbar. 16.3 g of 2,5-bis-(isopropoxycarbonyl)-3-methyl-4-[5-(butyloxycarbonyl)pentylaminocarbonyloxy]-thiophene are obtained as a viscous material. 1H--NMR 80 MHz CDCL3 δ-values OCH 2H m 5.0-5.5 ppm; OCH2 2H t 4.13 ppm; N--CH2 2H m 3.1-3.5 ppm; hetar-CH3 s 2.39 ppm.

Provenance & Evidence