Phenyl cyanate → 4-Dibutylamino-2-butynenitrile

Temperature

-70 °C

n-BuLi (2.2 M, 69.5 mL, 0.153 mol) was added dropwise to a cooled (-78° C.) solution of 3-dibutylaminopropyne (24.9 g, 0.149 mol) in anhydrous ether (175 mL) at a rate not allowing the temperature to rise above -50° C. The resulting solution was stirred (5minutes, -70° C.), then phenyl cyanate (19.6 g, 0.164 mol) was added dropwise at a rate not allowing the temperature to rise above -60° C. The resulting solution was stirred (45 minutes, -78° C.), then warmed (25° C.). The resulting dark brown solution was diluted with ether (250 mL), washed with 3.0 N NaOH (3×170 mL), washed with brine (1×170 mL), then dried (MgSO4), and concentrated in vacuo. The resulting oil was chromatographed on silica (chloroform) to yield 27.0 g (94.4%) of 4-dibutylamino-2-butynenitrile as a brown liquid. 1H NMR (250 MHz, CDCl3): δ 3.53 (s, 2H), 2.46 (t, 4H), 1.36 (m, 8H), 0.92 (t, 6H).

1. customto rise above -50° C
2. customto rise above -60° C
3. stirringThe resulting solution was stirred (45 minutes, -78° C.)
4. temperaturewarmed (25° C.)
5. washwashed with 3.0 N NaOH (3×170 mL)
6. washwashed with brine (1×170 mL)
7. dry with materialdried (MgSO4)
8. concentrationconcentrated in vacuo
9. customThe resulting oil was chromatographed on silica (chloroform)

ORD record

ord-961b8d7a8ae34fa3a1d256a748f858d8

Source dataset

uspto-grants-1992_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05162360