Lawesson's reagent → 2-Methyl-4-(trimethylsilanylmethyl-thiocarbamoyl)-benzoic acid methyl ester

HRID 1844637Notes

Reaction equation

HRID 1844637 reaction equation
[CH3:1][O:2][C:3](=[O:19])[C:4]1[CH:17]=[CH:16][C:7]([C:8]([NH:10][CH2:11][Si:12]([CH3:15])([CH3:14])[CH3:13])=O)=[CH:6][C:5]=1[CH3:18].COC1C=CC(P2(=S)SP(=S)(C3C=CC(OC)=CC=3)[S:29]2)=CC=1>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3](=[O:19])[C:4]1[CH:17]=[CH:16][C:7]([C:8](=[S:29])[NH:10][CH2:11][Si:12]([CH3:15])([CH3:14])[CH3:13])=[CH:6][C:5]=1[CH3:18]

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 675061012-methyl-N-trimethylsilanylmethyl-terephthalamic acid methyl ester

Product 1

HCID 866857032-Methyl-4-(trimethylsilanylmethyl-thiocarbamoyl)-benzoic acid methyl esterYield 95.6%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 2-methyl-N-trimethylsilanylmethyl-terephthalamic acid methyl ester (Example I7) (1.83 g) in toluene (50 ml) was added 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (Lawesson reagent) (2.65 g). The reaction mixture was stirred at ambient temperature for 30 minutes and then at 110° C. for 1.5 hours. The reaction mixture was concentrated and the residue purified by chromatography on silica gel (eluent: ethyl acetate/heptanes 1:5) to give 2-methyl-4-(trimethylsilanylmethyl-thiocarbamoyl)-benzoic acid methyl ester (1.85 g). 1H-NMR (400 MHz, CDCl3): 7.75-7.20 (m, 3H), 3.70 (s, 3H), 3.35 (m, 2H), 2.45 (s, 3H), 0.00 (s, 9H) ppm.

Workup

  1. waitat 110° C. for 1.5 hours
  2. concentrationThe reaction mixture was concentrated
  3. customthe residue purified by chromatography on silica gel (eluent: ethyl acetate/heptanes 1:5)

Sources & evidence

ORD record
ord-3e8a37c721814a4694a65fe43f4dc7b3
Source dataset
uspto-grants-2015_02
Patent number
US08946447B2

Reaction notes

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