Triphenylphosphine → methyl (RS)-3-(1-cyclopropyl-prop-2-ynyloxy)-4,5-dimethoxy-benzoate

HRID 964968Notes

Reaction equation

HRID 964968 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:10]=[C:11](O)[C:12]=1[O:13][CH3:14])[C:6]([O:8][CH3:9])=[O:7].[CH:16]1([CH:19]([OH:22])[C:20]#[CH:21])[CH2:18][CH2:17]1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O>C1(C)C=CC=CC=1>[CH:16]1([CH:19]([O:22][C:11]2[CH:10]=[C:5]([CH:4]=[C:3]([O:2][CH3:1])[C:12]=2[O:13][CH3:14])[C:6]([O:8][CH3:9])=[O:7])[C:20]#[CH:21])[CH2:18][CH2:17]1

Participants

6

Reactant 4

HCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 3431191-Cyclopropylprop-2-yn-1-olHCID 2733956Methyl 3-hydroxy-4,5-dimethoxybenzoate

Product 1

HCID 54377500methyl (RS)-3-(1-cyclopropyl-prop-2-ynyloxy)-4,5-dimethoxy-benzoate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Conditions

Temperature
5 °C

Procedure

63.6 g of methyl 3,4-dimethoxy-5-hydroxy-benzoate [E. Spath and H. Roder, Monatsh. fur Chemie, 43, 93 (1923)], 38.5 g of (RS)-1-cyclopropyl-prop-2-yn-1-ol and 118 g of triphenylphosphine were dissolved in 600 ml of toluene under argon and cooled to 5° C. A solution of 70 ml of diethyl azodicarboxylate in 150 ml of toluene was slowly added dropwise thereto at 5° C. over 90 min. The mixture was stirred at 5° C. for a further 1 hr. and at 20° C. for 3 hrs. Then, 300 ml of toluene were distilled off on a rotary evaporator and the suspension obtained was stirred in an ice bath for 30 min. The separated triphenylphosphine oxide was filtered off and the filtrate was evaporated. The resulting oil was chromatographed on silica gel with hexane/ethyl acetate 4:1, then 3:1. Crystallization was effected from diethyl ether and hexane. There was obtained methyl (RS)-3-(1-cyclopropyl-prop-2-ynyloxy)-4,5-dimethoxy-benzoate as white crystals.

Workup

  1. waitand at 20° C. for 3 hrs
  2. distillationThen, 300 ml of toluene were distilled off on a rotary evaporator
  3. customthe suspension obtained
  4. stirringwas stirred in an ice bath for 30 min
  5. filtrationThe separated triphenylphosphine oxide was filtered off
  6. customthe filtrate was evaporated
  7. customThe resulting oil was chromatographed on silica gel with hexane/ethyl acetate 4:1
  8. customCrystallization

Sources & evidence

ORD record
ord-26a6e4fe57844be886e38b37d5444c66
Source dataset
uspto-grants-1998_06
Patent number
US05773446

Reaction notes

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