Hydrochloric Acid → 3,3-Bis(methoxycarbonyl)-1,2,3,4-tetrahydroquinoline

HRID 863234Notes

Reaction equation

HRID 863234 reaction equation
C(OC([N:11]1[C:20]2[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH2:14][CH:13]([C:21]([O:23][CH3:24])=[O:22])[CH2:12]1)=O)C1C=CC=CC=1.C([N-]C(C)C)(C)C.[Li+].Cl[C:34]([O:36][CH3:37])=[O:35].Cl>O1CCCC1.[Pd]>[CH3:37][O:36][C:34]([C:13]1([C:21]([O:23][CH3:24])=[O:22])[CH2:14][C:15]2[C:20](=[CH:19][CH:18]=[CH:17][CH:16]=2)[NH:11][CH2:12]1)=[O:35]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6586Methyl chloroformateHCID 2724682Lithium diisopropylamideHCID 19697580N-Benzyloxycarbonyl-3(R,S)-methoxycarbonyl-1,2,3,4-tetrahydroquinoline

Product 1

HCID 196977683,3-Bis(methoxycarbonyl)-1,2,3,4-tetrahydroquinoline

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

1.00 g of N-benzyloxycarbonyl-3(R,S)-methoxycarbonyl-1,2,3,4-tetrahydroquinoline (Example 1s)) are deprotonated in 10 ml of tetrahydrofuran with excess lithium diisopropylamide (1.5 equivalents) under customary reaction conditions, and 0.80 ml of methyl chloroformate is then added at -70° C. After 30 min, the mixture is poured onto 0.1N hydrochloric acid and extracted with methylene chloride. The crude product obtained after customary further working up is dissolved in 30 ml of tetrahydrofuran and hydrogenated in the presence of 1.00 g of palladium-on-charcoal (10% of Pd) until the reaction has ended. After purification of the product over 100 g of silica gel (mobile phase B), 3,3-bis(methoxycarbonyl)-1,2,3,4-tetrahydroquinoline is obtained: Rf (B)=0.50.

Workup

  1. additionis then added at -70° C
  2. extractionextracted with methylene chloride
  3. customThe crude product obtained after customary
  4. customAfter purification of the product over 100 g of silica gel (mobile phase B)

Sources & evidence

ORD record
ord-b4a8a3a71d4245df98c1261db7403b41
Source dataset
uspto-grants-1998_02
Patent number
US05719141

Reaction notes

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