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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 72037Generated: October 25, 2026

Diisopropylethylamine → 6-(2-Methoxycarbonylamino-3-methyl-butyryl)-5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester

https://huagongshe.com/reaction/72037

Reaction equation

Participants

RoleNameHCIDCharge
ReactantDiisopropylethylamineHCID 81531—
ReactantMethanaminium, N-((dimethylamino)(3H-1,2,3-triazolo(4,5-b)pyridin-3-yloxy)methylene)-N-methyl-, hexafluorophosphate(1-) (1:1)HCID 9886157—
Reactant2-((Methoxycarbonyl)amino)-3-methylbutanoic acidHCID 13821101—
ReactantEthyl 5-oxa-6-azaspiro[3.4]octane-7-carboxylateHCID 59611538—
SolventDimethylformamideHCID 6228—
SolventEthyl AcetateHCID 8857—
Product6-(2-Methoxycarbonylamino-3-methyl-butyryl)-5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl esterHCID 6662064972.2%

Reaction Conditions

Temperature60 °C

Reaction Steps

To a solution of 2-methoxycarbonylamino-3-methyl-butyric acid (1.11 g, 6.33 mmol) and HATU (2.41 g, 6.34 mmol) in dimethylformamide (13 mL) was added a solution of 5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester (980 mg, 5.3 mmol) in dimethylformamide (13 mL). To the resulting reaction mixture was added diisopropylethylamine (1.85 mL, 10.6 mmol) and the reaction was heated to 60° C. for 16 hours. The reaction was diluted with ethyl acetate, washed with water and brine, dried (MgSO4) and concentrated. The resulting residue was purified by flash chromatography to give 6-(2-methoxycarbonylamino-3-methyl-butyryl)-5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester (1.31 g, 72%). LCMS-ESI+: calculated for C16H26N2O6: 342.18; observed [M+1]+: 342.90.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08822430B2
Source datasetuspto-grants-2014_09
ORD IDord-eba9becb8c734222a2370a6afdec18d9
Source noteuspto-grants-2014_09