Carbon tetrabromide → Methyl 15-bromopentadecanoate

HRID 926654

Reaction equation

HRID 926654 reaction equation
O[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][C:16]([O:18][CH3:19])=[O:17].C(Br)(Br)(Br)[Br:21].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.P>ClCCl>[Br:21][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][C:16]([O:18][CH3:19])=[O:17]

Participants

6

Reactant 4

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 24404PhosphineHCID 3496889Methyl 15-Hydroxypentadecanoate

Product 1

HCID 554136Methyl 15-bromopentadecanoateYield 90%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of methyl 15-hydroxypentadecanoate (4.2 g, 15.6 mmol, 1.0 eq) and carbon tetrabromide (5.7 g, 17.1 mmol, 1.1 eq) in dichloromethane (15 mL) cooled to 0° C., was added triphenyl phosphine (4.3 g, 17.1 mmol, 1.1 eq) in portions over 30 min with vigorous stirring. Upon addition of the phosphine, the colourless solution turned a pale brown colour and was stirred for an additional 2 hours at room temperature. The mixture was concentrated in vacuo (using a rotary evaporator attached to a diaphragm pump) to a brown oil. Hexane (200 mL) was quickly added and the resulting mixture was stirred for 15 minutes. The resultant white precipitate was removed by filtration, and the filtrate was concentrated in vacuo. The product was purified by silica gel chromatography (20:1 hexane:ethyl acetate), yielding methyl 15-bromopentadecanoate (4.6 g, 90%) as a colourless solid.

Workup

  1. concentrationThe mixture was concentrated in vacuo (
  2. customa rotary evaporator
  3. additionHexane (200 mL) was quickly added
  4. stirringthe resulting mixture was stirred for 15 minutes
  5. customThe resultant white precipitate was removed by filtration
  6. concentrationthe filtrate was concentrated in vacuo
  7. customThe product was purified by silica gel chromatography (20:1 hexane:ethyl acetate)

Sources & evidence

ORD record
ord-69f662158dc64f6387327d6ac8c284a3
Source dataset
uspto-grants-2016_03
Patent number
US09287114B2

Linked notes

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