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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 133728Generated: October 26, 2026

Ethylene Glycol → 1,5-Dioxa-9-azaspiro[5.5]undecane, 8,8,10,10-tetramethyl-

https://huagongshe.com/reaction/133728

Reaction equation

Participants

RoleNameHCIDCharge
ReactantEthylene GlycolHCID 174—
ReactantWaterHCID 962—
ReactantPhosphoric AcidHCID 1004—
ReactantTolueneHCID 1140—
Reactant2,2,6,6-Tetramethyl-4-piperidoneHCID 13220—
Product1,5-Dioxa-9-azaspiro[5.5]undecane, 8,8,10,10-tetramethyl-HCID 11961786—

Reaction Steps

Use of Phosphoric Acid 77 g of triacetonamine were initially charged in 240 g of toluene together with 47 g of ethylene glycol. Subsequently, sufficient phosphoric acid (63 g) was added that the reaction mixture showed an acidic pH (≦2) when tested with a moistened indicator paper. The reaction mixture was heated to reflux temperature and water of reaction formed was removed on a water separator. After approx. 3 hours, there was less than 10% of the desired product according to the gas chromatogram. Instead, a plurality of secondary components had formed which were not investigated further.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07390930B2
Source datasetuspto-grants-2008_06
ORD IDord-7875deca30664fefb1e356d47aae5457
Source noteuspto-grants-2008_06