p-Toluenesulfonic acid monohydrate → N,2,2-trimethyl-6-nitro-2H-1-benzopyran-4-carbothioamide

HRID 36068Notes

Reaction equation

HRID 36068 reaction equation
[CH3:1][NH:2][C:3]([CH:5]1[C:10]2[CH:11]=[C:12]([N+:15]([O-:17])=[O:16])[CH:13]=[CH:14][C:9]=2[O:8][C:7]([CH3:19])([CH3:18])[CH:6]1O)=[S:4].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][NH:2][C:3]([C:5]1[C:10]2[CH:11]=[C:12]([N+:15]([O-:17])=[O:16])[CH:13]=[CH:14][C:9]=2[O:8][C:7]([CH3:19])([CH3:18])[CH:6]=1)=[S:4]

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 15234732N,2,2-trimethyl-3,4-dihydro-3-hydroxy-6-nitro-2H-1-benzopyran-4-carbothioamide

Product 1

HCID 10423672N,2,2-trimethyl-6-nitro-2H-1-benzopyran-4-carbothioamideYield 49.4%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 7.0 g of N,2,2-trimethyl-3,4-dihydro-3-hydroxy-6-nitro-2H-1-benzopyran-4-carbothioamide, 3.0 g of p-toluenesulfonic acid monohydrate, and 300 ml of toluene was heated at reflux for 1 hour. The solvent was removed from the reaction mixture by distillation, and the residue was purified by silica gel column chromatography (developing solution: CH2Cl2). Recrystallizatlon from a mixed solvent of CH2Cl2, diethyl ether, and hexane gave 3.25 g of N,2,2-trimethyl-6-nitro-2H-1-benzopyran-4-carbothioamide represented by formula shown below.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 1 hour
  3. customThe solvent was removed from the reaction mixture by distillation
  4. customthe residue was purified by silica gel column chromatography (developing solution: CH2Cl2)

Sources & evidence

ORD record
ord-67389c1b84bf49a895cf2addc80c2860
Source dataset
uspto-grants-1995_05
Patent number
US05412117

Reaction notes

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