Tetrahydrofuran → HCID 67194883, compound

Participants

Reaction Steps

A solution of N-methylisobutylamine (2.2 mL, 18 mmol) and triethylamine (5.5 mL, 39 mmol) in THF (60 mL) was added dropwise to a stirred solution of triphosgene (1.98 g, 6.7 mmol) in THF (37 mL) at room temperature. The reaction mixture was stirred overnight. Then, a solution of N-methylisobutylamine (2.2 mL, 18 mmol) and triethylamine (5.5 mL, 40 mmol) in THF (35 mL) was added. The reaction mixture was stirred overnight at reflux temperature. The reaction mixture was filtered and the filtrate was evaporated to dryness, yielding N-methyl-N-isobutyl-N′,N′-dicyclohexylurea as an orange oil. Yield: 3.3 g (92%). Oxalyl chloride (1.45 mL, 17 mmol) was added to a stirred solution of the urea (3.3 g, 16 mmol) in THF (70 mL). The reaction mixture was heated to reflux overnight and evaporated to dryness. Ammonia in methanol (7 mL, 49 mmol, 7 M solution in methanol) was added to a suspension of the formed solid in THF. The reaction mixture was heated to reflux overnight and evaporated to dryness. The product was neutralized and purified by treatment with aqueous sodium hydroxide solution. The organic layer was extracted with diethyl ether and dried over magnesium sulfate. Evaporation to dryness yielded the desired guanidine as a brown oil. Yield: 2.78 g (82%). 1H NMR (CDCl3, 300 MHz): δ 0.74 (d, 12 H), 1.76 (sept, 2 H), 2.66 (s, 6 H), 2.85 (d, 4H) ppm. 13C NMR (CDCl3, 75 MHz): δ 19.8, 26.3, 37.1, 57.6, 165.6 ppm.

Provenance & Evidence