Iodine → HCID 55301267, compound

In a flame-dried flask, under an argon atmosphere, magnesium (7.8 g, 0.33 mol) and a small crystal of iodine in just enough THF to cover the magnesium was heated to a gentle reflux until the color had disappeared. Approximately 10% of a solution of 4-bromo-1-buten (32.5 mL, 0.321 mol) in THF (100 mL) was added all at once and reflux was continued until a brown coloration appeared. The remainder of the solution was added dropwise with continued reflux. After the addition was complete heating was maintained for 10 min, at which point almost all of the Mg had dissolved. The Grignard reagent solution was added to a second cooled (ice-bath) solution of 4-chloro-N-methoxy-N-methylbutanamide (21.3 g, 0.128 mol) in THF (200 mL). The resulting mixture was stirred for at room temperature for 2 h, poured into a mixture of ether and saturated aqueous ammonium chloride. The layers were separated and the aqueous phase was extracted with ether. The combined extracts were dried over Mg2SO4, filtered and concentrated under reduced pressure to give crude 1-chlorooct-7-en-4-one (17 g, 85%) as yellow liquid. 1H NMR (CDCl3, 500 MHz) δ 5.93-5.69 (m, 1H), 5.11-4.92 (m, 2H), 3.58 (t, J=6.5 Hz, 2H), 2.65-2.50 (m, 4H), 2.41-2.26 (m, 2H), 2.11-1.98 (qw, J=6.5 Hz, 2H).

1. temperaturea gentle reflux until the color
2. temperaturereflux
3. additionThe remainder of the solution was added dropwise with continued reflux
4. additionAfter the addition
5. temperaturewas complete heating
6. dissolutionhad dissolved
7. customThe layers were separated
8. extractionthe aqueous phase was extracted with ether
9. dry with materialThe combined extracts were dried over Mg2SO4
10. filtrationfiltered
11. concentrationconcentrated under reduced pressure

ORD record

ord-8a8417fdf2514a42be65bb0ec7308bbf

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266908B2