2-Butanamine, 2-methyl- → (1Z)-1-[3-(2-methoxyethyl)-4,5-dimethyl-1,3-thiazol-2-ylidene]-3-(2-methylbutan-2-yl)urea

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Reaction Steps

To a solution of 1,1-dimethylpropylamine (174 mg, 2.0 mmole) in 19 mL of THF and 1 mL of N,N-diisopropylethyl amine was added 4-nitrophenyl chloroformate (403 mg, 2.0 mmole). The solution was irradiated in a sealed tube placed in a single node microwave at 70° C. for 300 sec (maximum power 300 W) with stirring. The resulting solution was cooled to room temperature and 3-(2-methoxyethyl)-4,5-dimethyl-3H-thiazol-2-ylideneamine hydrobromide (587 mg, 2.2 mmole) from Example 12A was added. The sealed tube was irradiated at 120° C. for 1800 sec with stirring. The mixture was cooled and the volatile components were removed under reduced pressure. The residue was partitioned between water and ethyl acetate. The phases were separated and organic extract was dried over anhydrous Na2SO4, filtered, and concentrated. Purification by column chromatography (SiO2, 0-70% ethyl acetate/hexanes gradient) afforded the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 0.76 (t, J=7 Hz, 3H) 1.20 (s, 6H) 1.66 (d, J=7 Hz, 2H) 2.06 (s, 3H) 2.11 (s, 3H) 3.30 (s, 3H) 3.55 (t, J=5 Hz, 2H) 4.06 (t, J=5 Hz, 2H) 6.13 (s, 1H)), MS (DCI/NH3) m/z 300 (M+H)+.

Provenance & Evidence