Pyridine → Ethyl (-)-lactate triflate

HRID 530107Notes

Reaction equation

HRID 530107 reaction equation
[F:1][C:2]([F:15])([F:14])[S:3]([O:6]S(C(F)(F)F)(=O)=O)(=[O:5])=[O:4].[CH2:16]([O:18][C:19](=[O:23])[CH:20](O)[CH3:21])[CH3:17].N1C=CC=CC=1>ClCCl>[F:1][C:2]([F:15])([F:14])[S:3]([O:6][CH:20]([CH3:21])[C:19]([O:18][CH2:16][CH3:17])=[O:23])(=[O:5])=[O:4]

Participants

5

Reactant 3

HCID 1049PyridineHCID 7344Ethyl LactateHCID 67749Trifluoromethanesulfonic anhydride

Product 1

HCID 4251232Ethyl (-)-lactate triflateYield 88%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of trifluoromethanesulfonic anhydride (30 mL, 170 mmol) in anhydrous dichloromethane (50 mL) was added drop-wise a solution of 2-hydroxypropanoic acid ethyl ester (20 g, 170 mmol) and pyridine (14 mL) in dichloromethane (50 mL) at 0° C. (Ice bath) over a period of 1 h under nitrogen. The ice bath was then removed and the reaction mixture was stirred for additional 2 h. The inorganic salt was then filtered off and the organic solution was washed with water, dried over sodium sulfate, and evaporated to give desired product as pink colored oil (37.4 g, 88%) which was used as such for the next step. 1HNMR (300 MHz, CDCl3): δ 1.38 (t, J=4.8 Hz, 3H), 1.77 (d, J=4.8 Hz, 3H), 4.32-4.37 (m, 2H) and 5.28 (q, J=6.9 Hz, 1H).

Workup

  1. customThe ice bath was then removed
  2. filtrationThe inorganic salt was then filtered off
  3. washthe organic solution was washed with water
  4. dry with materialdried over sodium sulfate
  5. customevaporated

Sources & evidence

ORD record
ord-030777a5b74c4a82b2c2fae1a17b9507
Source dataset
uspto-grants-2016_05
Patent number
US09351974B2

Reaction notes

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