Ethyl propiolate → HCID 68327941, compound

HRID 2274856Notes

Reaction equation

HRID 2274856 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2OC(=O)[S:10][N:9]=2)=[CH:4][CH:3]=1.[C:14]([O:18][CH2:19][CH3:20])(=[O:17])[C:15]#[CH:16]>ClC1C=CC=CC=1Cl>[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:16]=[C:15]([C:14]([O:18][CH2:19][CH3:20])=[O:17])[S:10][N:9]=2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 12182Ethyl propiolateHCID 14087130HCID 14087130, compound

Product 1

HCID 68327941HCID 68327941, compoundYield 32%

Reagents, catalysts & solvents 1

HCID 72391,2-DichlorobenzeneSolvent

Conditions

Temperature
135 °C

Procedure

To a stirred solution of 5-(4-fluorophenyl)-1,3,4-oxathiazol-2-one (42.80 g, 217.1 mmol) in o-dichlorobenzene (600 mL) was added ethyl propiolate (66.0 mL, 651 mmol). The mixture was heated overnight at 135° C. and concentrated. The residual oil was purified by flash chromatography using a hexane/ethyl acetate gradient to afford ethyl 3-(4-fluorophenyl)isothiazole-5-carboxylate as a pale golden solid (17.35 g, 32%). The more polar, ethyl 3-(4-fluorophenyl)isothiazole-4-carboxylate isomer (generated in 57/43 ratio versus the desired product) was discarded.

Workup

  1. concentrationconcentrated
  2. customThe residual oil was purified by flash chromatography

Sources & evidence

ORD record
ord-6bc323108b634a6f9d3f676f63d19e6a
Source dataset
uspto-grants-2015_09
Patent number
US09126993B2

Reaction notes

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