Diisopropylamine → (5-Chloroindol-3-yl)methyl-2-dimethylamino-2-oxazolin-4-one

HRID 2227522Notes

Reaction equation

C(NC(C)C)(C)C.C([Li])CCC.[CH3:13][N:14]([CH3:21])[C:15]1[O:16][CH2:17][C:18](=[O:20])[N:19]=1.C(OC([N:32]1[C:40]2[C:35](=[CH:36][C:37]([Cl:41])=[CH:38][CH:39]=2)[C:34]([CH2:42]Cl)=[CH:33]1)=O)C1C=CC=CC=1>O1CCCC1.CCCCCC.O>[Cl:41][C:37]1[CH:36]=[C:35]2[C:40](=[CH:39][CH:38]=1)[NH:32][CH:33]=[C:34]2[CH2:42][CH:17]1[O:16][C:15]([N:14]([CH3:21])[CH3:13])=[N:19][C:18]1=[O:20]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of diisopropylamine (1.18 ml) in tetrahydrofuran (24 ml) was added a 1.6 M solution (5.24 ml) of n-butyllithium in hexane under ice cooling. The mixture was cooled to −78° C., to which was added 2-dimethylamino-2-oxazolin-4-one (1.07 g). The mixture was stirred for 30 minutes at room temperature and cooled again to −78° C. 1-benzyloxycarbonyl-5-chloro-3-chloromethylindol (1.40 g) was added. The whole was stirred at −78° C. to −40° C. for 30 minutes, at 0° C. for 2 hours and at room temperature for 40 minutes respectively. To the reaction mixture was added water and the whole was extracted with ethyl acetate. The extract was dried over magnesium sulfate and concentrated to give a residue, which was subjected to silica gel chromatography. Elution with hexane-ethyl acetate (1:1) gave 5-[(5-chloroindol-3-yl)methyl-2-dimethylamino-2-oxazolin-4-one (232 mg) as a crystal.

Workup

temperaturecooled again to −78° C
stirringThe whole was stirred at −78° C. to −40° C. for 30 minutes, at 0° C. for 2 hours and at room temperature for 40 minutes respectively
extractionthe whole was extracted with ethyl acetate
dry with materialThe extract was dried over magnesium sulfate
concentrationconcentrated
customto give a residue, which
washElution with hexane-ethyl acetate (1:1)

Sources & evidence

ORD record: ord-ad792d3f718c4c74861ae04265556ee5
Source dataset: uspto-grants-2002_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06414003B1

Reaction notes

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