Lawesson's reagent → 7-chloro-5-(2-pyridyl)-3H-1,4-benzodiazepine-2(1H)-thione

HRID 566302Notes

Reaction equation

HRID 566302 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10](=O)[CH2:9][N:8]=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][N:14]=3)[C:6]=2[CH:19]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:29])=CC=1>N1C=CC=CC=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=S)=CC=1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10](=[S:29])[CH2:9][N:8]=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][N:14]=3)[C:6]=2[CH:19]=1

Participants

5

Reactant 2

HCID 87949Lawesson's reagentHCID 2874017-Chloro-5-(2-pyridinyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one

Product 1

HCID 212659987-chloro-5-(2-pyridyl)-3H-1,4-benzodiazepine-2(1H)-thioneYield 185.1%

Reagents, catalysts & solvents 2

HCID 87949Lawesson's reagentCatalystHCID 1049PyridineSolvent

Conditions

Temperature
100 °C

Procedure

A solution of 18.5 g of 7-chloro-5-(2-pyridyl)-3H-1,4-benzodiazepin-2(1H)-one (N. Ch. Hindley, T. M. McClymont & G. O. Chase; F. Hoffmann La Roche and Co., A. G., German Offenlegungsschrift 2,233,483, 1973) in 150 ml of pyridine was treated with 14.2 g of Lawesson reagent and the mixture was stirred at 100° C. for 2 h. After the addition of 1.0 g of Lawesson reagent the mixture was stirred at 100° C. for a further 0.5 h. and then evaporated in a vacuum. The residue was poured into 500 ml of saturated aqueous sodium hydrogen carbonate solution and the precipitate was filtered off (22 g). The red crystals were suspended in 100 ml of boiling methanol. After cooling 100 ml of diethyl ether were added and the crystals were filtered off. There were obtained 18.7 g of 7-chloro-5-(2-pyridyl)-3H-1,4-benzodiazepine-2(1H)-thione of m.p. 217-218° C.

Workup

  1. stirringwas stirred at 100° C. for a further 0.5 h.
  2. customevaporated in a vacuum
  3. additionThe residue was poured into 500 ml of saturated aqueous sodium hydrogen carbonate solution
  4. filtrationthe precipitate was filtered off (22 g)
  5. temperatureAfter cooling 100 ml of diethyl ether
  6. additionwere added
  7. filtrationthe crystals were filtered off

Sources & evidence

ORD record
ord-854be072b7144b2081b527bf12ddc5b7
Source dataset
uspto-grants-2001_01
Patent number
US06174881B1

Reaction notes

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