Hydrochloric Acid → 4-([(9H-Fluoren-9-ylmethoxy)carbonyl]amino)-4-methylpentanoic acid

HRID 1628094Notes

Reaction equation

[NH2:1][C:2]([CH3:9])([CH3:8])[CH2:3][CH2:4][C:5]([OH:7])=[O:6].C([O-])([O-])=O.[Na+].[Na+].[C:16](Cl)([O:18][CH2:19][CH:20]1[C:32]2[C:27](=[CH:28][CH:29]=[CH:30][CH:31]=2)[C:26]2[C:21]1=[CH:22][CH:23]=[CH:24][CH:25]=2)=[O:17].Cl>O1CCOCC1>[CH:31]1[C:32]2[CH:20]([CH2:19][O:18][C:16]([NH:1][C:2]([CH3:9])([CH3:8])[CH2:3][CH2:4][C:5]([OH:7])=[O:6])=[O:17])[C:21]3[C:26](=[CH:25][CH:24]=[CH:23][CH:22]=3)[C:27]=2[CH:28]=[CH:29][CH:30]=1

Participants

Conditions

Temperature: 0 °C

Procedure

A stirred solution containing 4-amino-4-methylpentanoic acid (0.90 g, 6.86 mmol, Chembridge), Na2CO3 (2.9 g, 27. mmol), and 1,4-dioxane (10 mL) was cooled in an ice bath and Fmoc-Cl (2.1 mg, 8.2 mmol) dissolved in 1,4-dioxane (10 mL) was added in over about 2 min. The mixture was stirred at about 0° C. for about 1 h and then allowed to warm to rt. The mixture was neutralized with aqueous 6 N HCl and extracted with EtOAc (3×25 mL). The combined organic layers were dried over MgSO4, filtered and concentrated under reduced pressure. The crude material was purified by flash chromatograph (40 g silica gel column, 10-60% EtOAc/Heptane) to give 4-(((9H-fluoren-9-yl)methoxy)carbonylamino)-4-methylpentanoic acid the title compound (1.2 g, 49%): LC/MS (Table 2, Method b) Rt=2.31 min.; MS m/z: 352 (M−H)+.

Workup

temperaturewas cooled in an ice bath
additionwas added in over about 2 min
temperatureto warm to rt
extractionextracted with EtOAc (3×25 mL)
dry with materialThe combined organic layers were dried over MgSO4
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe crude material was purified by flash chromatograph (40 g silica gel column, 10-60% EtOAc/Heptane)

Sources & evidence

ORD record: ord-1e4f452c56214c83b58404e50e6308d1
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08785639B2

Reaction notes

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