Toluene → Methyl cis-3-t-butoxycarbonylamino-1-(2,4-dimethoxybenzyl)-4-oxoazetidine-2-carboxylate

HRID 2050385

Reaction equation

HRID 2050385 reaction equation
[NH2:1][C@H:2]1[C:5](=[O:6])[N:4]([CH2:7][C:8]2[CH:13]=[CH:12][C:11]([O:14][CH3:15])=[CH:10][C:9]=2[O:16][CH3:17])[C@H:3]1[C:18]([O:20][CH3:21])=[O:19].C(N(CC)CC)C.C(Cl)(Cl)=O.C(#N)C.[C:36](=[O:38])=[O:37].[C:39]1([CH3:45])[CH:44]=CC=C[CH:40]=1>C1C=CC=CC=1>[C:39]([O:37][C:36]([NH:1][C@H:2]1[C:5](=[O:6])[N:4]([CH2:7][C:8]2[CH:13]=[CH:12][C:11]([O:14][CH3:15])=[CH:10][C:9]=2[O:16][CH3:17])[C@H:3]1[C:18]([O:20][CH3:21])=[O:19])=[O:38])([CH3:45])([CH3:44])[CH3:40]

Participants

7

Reactant 5

HCID 1140TolueneHCID 6371PhosgeneHCID 8471TriethylamineHCID 18632686Methyl cis-1-(2,4-Dimethoxybenzyl)-3-amino-4-oxoazetidine-2-carboxylateHCID 86587134Acetonitrile dry ice

Product 1

HCID 70577863Methyl cis-3-t-butoxycarbonylamino-1-(2,4-dimethoxybenzyl)-4-oxoazetidine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A solution of 5.5 g (18.8 mmole) of methyl cis-3-amino-1-(2,4-dimethoxybenzyl)-4-oxoazetidine-2-carboxylate in 100 ml of dry toluene was cooled to -78° and 2.5 ml (18.8 mmole) of triethylamine was added followed by rapid addition of 35 ml (42 mmole) of a 12% solution of phosgene in benzene. The mixture was stirred 15 min at -78°, 3 hours at -45° (acetonitrile-dry ice), then warmed to room temperature and concentrated to half volume in vacuo. To the resulting solution was added 50 ml of t-butanol and the mixture was stirred at room temperature overnight. The solvents were removed in vacuo and the residue diluted with ethyl acetate and filtered. The filtrate was transferred to a separatory funnel and washed with 5% aqueous sodium bicarbonate, 5% hydrochloric acid and brine, dried (MgSO4) and evaporated to dryness. Recrystallization of the crude, crystalline product from ether gave methyl cis-3-t-butoxycarbonylamino-1-(2,4-dimethoxybenzyl)-4-oxoazetidine-2-carboxylate, m.p. 134°-135°.

Workup

  1. concentrationconcentrated to half volume in vacuo
  2. additionTo the resulting solution was added 50 ml of t-butanol
  3. customThe solvents were removed in vacuo
  4. additionthe residue diluted with ethyl acetate
  5. filtrationfiltered
  6. customThe filtrate was transferred to a separatory funnel
  7. washwashed with 5% aqueous sodium bicarbonate, 5% hydrochloric acid and brine
  8. dry with materialdried (MgSO4)
  9. customevaporated to dryness
  10. customRecrystallization of the crude, crystalline product from ether

Sources & evidence

ORD record
ord-e8a4624826a840949d812eca1a547f24
Source dataset
uspto-grants-1980_04
Patent number
US04200572

Linked notes

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