1,2-Dichloroethane → HCID 68349584, compound

HRID 1507977Notes

Reaction equation

HRID 1507977 reaction equation
C(Cl)CCl.[C:5]([O:9][C:10]([NH:12][C@@H:13]([C@H:15]([C:18]1[O:19][CH:20]=[C:21]([C:23]([OH:25])=O)[N:22]=1)[CH2:16][CH3:17])[CH3:14])=[O:11])([CH3:8])([CH3:7])[CH3:6].C1C=CC2N(O)N=[N:32]C=2C=1>ClCCl>[C:5]([O:9][C:10](=[O:11])[NH:12][C@@H:13]([C@H:15]([C:18]1[O:19][CH:20]=[C:21]([C:23](=[O:25])[NH2:32])[N:22]=1)[CH2:16][CH3:17])[CH3:14])([CH3:6])([CH3:7])[CH3:8]

Participants

5

Reactant 3

HCID 111,2-DichloroethaneHCID 757711-HydroxybenzotriazoleHCID 68291765HCID 68291765, compound

Product 1

HCID 68349584HCID 68349584, compoundYield 100%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1N aqueous sodium hydroxide (5.69 ml, 5.69 mmol) was added in one portion to a solution of methyl 2-((2R,3R)-2-((tert-butoxycarbonyl)amino)pentan-3-yl)oxazole-4-carboxylate (711 mg, 2.28 mmol) in anhydrous THF (9.11 ml). The reaction was allowed to stir at room temperature for 3.5 hours before evaporating the organic in vacuo. The remaining aqueous was cooled to 0° C. and acidified to pH 4 using 1N HCl. The aqueous phase was then extracted with ethyl acetate (3×25 mL). The aqueous pH was re-checked and judged to be ˜pH 6-7. A small amount of 1N HCl was added to re-acidify the aqueous layer which was once again extracted with an additional portion of ethyl acetate (1×25 mL). The combined organics were dried (MgSO4) and evaporated in vacuo to give crude 2-((2R,3R)-2-((tert-butoxycarbonyl)amino)pentan-3-yl)oxazole-4-carboxylic acid (679 mg, 2.28 mmol, 100% yield) as a white solid which was used immediately in the next reaction. EDC (545 mg, 2.84 mmol) was added in one portion to a mixture of 2-((2R,3R)-2-((tert-butoxycarbonyl)amino)pentan-3-yl)oxazole-4-carboxylic acid (679 mg, 2.28 mmol) and HOBT (436 mg, 2.84 mmol) in anhydrous dichloromethane (23.0 ml) and the reaction allowed to stir at room temperature under a nitrogen atmosphere for 30 minutes. Ammonia was then bubbled through for approximately 5 minutes and the resulting white suspension allowed to stir at room temperature overnight. The reaction was then evaporated in vacuo and the residue partitioned between ethyl acetate (25 mL) and water (25 mL). The organic layer was then dried (MgSO4) and evaporated in vacuo to give tert-butyl-((2R,3R)-3-(4-carbamoyloxazol-2-yl)pentan-2-yl)carbamate (677 mg, 2.28 mmol, 100% yield) which was used immediately in the next step. LC/MS: M+H+320.15, ret. time=1.89 min. Column: Phenomenex, 2.0×30 mm, 2.5-μm particles; Mobile Phase A: 10:90 methanol:water with 0.05% TFA; Mobile Phase B: 90:10 methanol:water with 0.05% TFA; Temperature: 50° C.; Gradient: 0-100% B over 3 minutes, then a 0.75-minute hold at 100% B; Flow: 1.11 mL/min. HPLC: ret. time=2.73 min. Column: YMC CombiScreen ODS-A, 4.6×50 mm; Mobile Phase A: 10:90 methanol:water with 0.2% H3PO4; Mobile Phase B: 90:10 methanol:water with 0.2% H3PO4; Temperature: 50° C.; Gradient: 0-100% B over 4 minutes, then a 0.75-minute hold at 100% B; Flow: 4 mL/min.

Workup

  1. customwas used immediately in the next reaction
  2. customAmmonia was then bubbled through for approximately 5 minutes
  3. stirringto stir at room temperature overnight
  4. customThe reaction was then evaporated in vacuo
  5. customthe residue partitioned between ethyl acetate (25 mL) and water (25 mL)
  6. dry with materialThe organic layer was then dried (MgSO4)
  7. customevaporated in vacuo

Sources & evidence

ORD record
ord-b663b4aff59348bd8a4f84f53052e714
Source dataset
uspto-grants-2015_12
Patent number
US09221826B2

Reaction notes

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