tert-Butyl piperazine-1-carboxylate → Tert-butyl 4-(4-chloro-1,2,5-thiadiazol-3-yl)piperazine-1-carboxylate

HRID 1978842Notes

Reaction equation

HRID 1978842 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Cl:14][C:15]1[N:19](Cl)[S:18][NH:17][CH:16]=1>CN(C)C=O.C(OCC)C>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:16]2[C:15]([Cl:14])=[N:19][S:18][N:17]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 2

HCID 143452tert-Butyl piperazine-1-carboxylateHCID 21202046HCID 21202046, compound

Product 1

HCID 15524001Tert-butyl 4-(4-chloro-1,2,5-thiadiazol-3-yl)piperazine-1-carboxylate

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6228DimethylformamideSolvent

Procedure

Piperazine-1-carboxylic acid tert-butyl ester (10 g, 0.054 m) was dissolved in anhydrous dimethylformamide (DMF, 50 mL) under nitrogen in a single-necked round bottomed flask. The clear solution was placed in a preheated oil bath (50 C-60 C). 4,5-Dichloro-[1,2,5]thiadiazole (5.0 mL, 0.054 m) was added and the reaction mixture was allowed to stir for 24 h. A yellow solution containing a white solid was observed. After cooling to room temperature, the mixture was diluted with an equal volume of anhydrous ethyl ether and stirred for 5 minutes. The solid was removed by filtration and the yellow filtrate was concentrated under aspirator vacuum to remove ether and then evaporated under oil pump vacuum to remove DMF. The yellow residue was dried at oil pump vacuum overnight to give 9.91 g of 4-(4-chloro-[1,2,5]thiadiazol-3-yl)piperazine-1-carboxylic acid tert-butyl ester. Two recrystallizations of crude product from hexane gave white crystals: mp 83-86° C.

Workup

  1. customThe clear solution was placed in a preheated oil bath
  2. additionA yellow solution containing a white solid
  3. stirringstirred for 5 minutes
  4. customThe solid was removed by filtration
  5. concentrationthe yellow filtrate was concentrated under aspirator vacuum
  6. customto remove ether
  7. customevaporated under oil pump vacuum
  8. customto remove DMF
  9. customThe yellow residue was dried at oil pump vacuum overnight

Sources & evidence

ORD record
ord-d25ee1afe93c4dd986cedda7c47b0fe4
Source dataset
uspto-grants-2001_05
Patent number
US06239134B1

Reaction notes

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