Triphenylphosphine → 4-Cyclopentyl-6,7-dihydro-6-methyl-1,4-thiazepin-2,5-(3H,4H)-dione

HRID 35355

Reaction equation

HRID 35355 reaction equation
[CH:1]1([N:6]([C:11](=[O:16])[CH:12]([CH3:15])[CH2:13][SH:14])[CH2:7][C:8](O)=[O:9])[CH2:5][CH2:4][CH2:3][CH2:2]1.C1C=C(SSC2N=CC=CC=2)N=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C1(C)C=CC=CC=1>[CH:1]1([N:6]2[C:11](=[O:16])[CH:12]([CH3:15])[CH2:13][S:14][C:8](=[O:9])[CH2:7]2)[CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 11776TriphenylphosphineHCID 650932,2'-Dipyridyl disulfideHCID 13469595(S)-[Cyclopentyl-(3-mercapto-2-methyl-propionyl)-amino]-acetic acid

Product 1

HCID 129236724-Cyclopentyl-6,7-dihydro-6-methyl-1,4-thiazepin-2,5-(3H,4H)-dione

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent3×

Procedure

A solution of N-cyclopentyl-N-(3-mercapto-2-methylpropanoyl)glycine (2.0 g., 8.1 mmol) in 125 ml of toluene was freed of air by bubbling nitrogen through it. To this solution was then added 2,2'-dipyridyldisulfide (2.7 g., 12.2 mmol) and triphenylphosphine (3.2 g., 12.2 mmol) and the resulting solution was stirred under nitrogen for 5 hours. This solution was then diluted to 250 ml with toluene and added at a rate of 20-25 ml/hr to 2 l of reluxing toluene under nitrogen. The resulting mixture was stirred at reflux for 48 hours and then cooled to room temperature. The solution was washed successively with 0.1N hydrochloric acid saturated sodium bicarbonate, water and brine, dried over anhydrous magnesium sulfate, and then filtered and concentrated under vacuum. The resulting solid material was dissolved in 25% ethyl acetate/hexane, filtered to remove the triphenyl phosphine oxide which crystallized, and purified by medium pressure liquid chromatography, eluting with 25% ethyl acetate/hexane, to give 0.8 g. of a pale yellow solid. This solid was recrystallized from 10% ethyl acetate/hexane to give 0.5 g (27%) of 4-cyclopentyl-6,7-dihydro-6-methyl-1,4-thiazapen-2,5-(3H,4H)-dione as a white crystalline solid, mp. 77°-79°.

Workup

  1. customby bubbling nitrogen through it
  2. temperatureat reflux for 48 hours
  3. washThe solution was washed successively with 0.1N hydrochloric acid saturated sodium bicarbonate, water and brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under vacuum
  7. dissolutionThe resulting solid material was dissolved in 25% ethyl acetate/hexane
  8. filtrationfiltered
  9. customto remove the triphenyl phosphine oxide which
  10. customcrystallized
  11. custompurified by medium pressure liquid chromatography
  12. washeluting with 25% ethyl acetate/hexane
  13. customto give 0.8 g
  14. customThis solid was recrystallized from 10% ethyl acetate/hexane
  15. customto give 0.5 g (27%) of 4-cyclopentyl-6,7-dihydro-6-methyl-1,4-thiazapen-2,5-(3H,4H)-dione as a white crystalline solid, mp. 77°-79°

Sources & evidence

ORD record
ord-f70f05fe4b4d40d7853ee692b69a4e26
Source dataset
uspto-grants-1988_08
Patent number
US04766210

Linked notes

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