Lawesson's reagent → N-(3-Chloro-4-fluorophenyl)-4-[(triisopropylsilyl)oxy]methyl-1,2,5-oxadiazole-3-carbothioamide

HRID 2097607Notes

Reaction equation

HRID 2097607 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([NH:9][C:10]([C:12]2[C:16]([CH2:17][O:18][Si:19]([CH:26]([CH3:28])[CH3:27])([CH:23]([CH3:25])[CH3:24])[CH:20]([CH3:22])[CH3:21])=[N:15][O:14][N:13]=2)=O)[CH:5]=[CH:6][C:7]=1[F:8].COC1C=CC(P2(=S)SP(C3C=CC(OC)=CC=3)(=S)[S:38]2)=CC=1>C1(C)C=CC=CC=1.C(Cl)(Cl)Cl>[Cl:1][C:2]1[CH:3]=[C:4]([NH:9][C:10]([C:12]2[C:16]([CH2:17][O:18][Si:19]([CH:26]([CH3:28])[CH3:27])([CH:23]([CH3:25])[CH3:24])[CH:20]([CH3:22])[CH3:21])=[N:15][O:14][N:13]=2)=[S:38])[CH:5]=[CH:6][C:7]=1[F:8]

Participants

5

Reactant 2

HCID 87949Lawesson's reagentHCID 58941856N-(3-Chloro-4-fluorophenyl)-4-[(triisopropylsilyl)oxy]methyl-1,2,5-oxadiazole-3-carboxamide

Product 1

HCID 58941860N-(3-Chloro-4-fluorophenyl)-4-[(triisopropylsilyl)oxy]methyl-1,2,5-oxadiazole-3-carbothioamideYield 78.5%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6212ChloroformSolvent

Procedure

Into a round bottom flask was placed a solution of N-(3-chloro-4-fluorophenyl)-4-[(triisopropylsilyl)oxy]methyl-1,2,5-oxadiazole-3-carboxamide (4.1 g, 9.5 mmol) in anhydrous toluene (79 mL) under N2. 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (7.7 g, 19 mmol) was added while stirring at ambient temperature. After addition, the resulting suspension was stirred and heated at 100° C. for 20 hrs. A considerable amount of solid precipitate was filtered off while the reaction was still hot, which was residual Lawesson's reagent. The liquid was then concentrated to give a yellow oil which was dissolved in chloroform and loaded onto a 330 g silica column eluting with 25% ethyl acetate/hexane to yield the desired product (3.31 g, 78%). 1H NMR (400 MHz, DMSO-d6) δ: 12.87 (s, 1H), 7.8 (ddd, J=8.9, 4.3, 2.7 Hz, 1H), 8.21 (dd, J=6.8, 2.7 Hz, 1H) 7.55 (dd, J=9.0, 9.0 Hz, 1H), 5.14 (s, 2H), 1.07 (m, 3H), 0.97 (d, J=7.0, 18H); (M+H)+: m/z=444.134.

Workup

  1. customInto a round bottom flask was placed
  2. additionAfter addition
  3. stirringthe resulting suspension was stirred
  4. temperatureheated at 100° C. for 20 hrs
  5. filtrationA considerable amount of solid precipitate was filtered off while the reaction
  6. concentrationThe liquid was then concentrated
  7. customto give a yellow oil which
  8. washeluting with 25% ethyl acetate/hexane

Sources & evidence

ORD record
ord-edc81acb35824d988c8e0044d1c3e7da
Source dataset
uspto-grants-2013_05
Patent number
US08450351B2

Reaction notes

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