Triethylamine → HCID 21924718, compound

A 500 ml 3 neck flask was charged with N-hydroxy-5-norbornene-2,3-dicarboximide (22.39 g, 0.125 mol). The flask was fitted with a condenser, a dropping funnel, a nitrogen bubbler and a magnetic stirrer. 1,1,1,3,3,3-Hexamethyldisilazane (14.50 ml, 11.10 g, 68.75 mmol) was added via the dropping funnel followed by one drop of chlorotrimethylsilane as catalyst. The suspension was brought to a gentle reflux and heated thereat for 3 h. The resulting solution solidified upon cooling to room temperature. This solid was presumed to be the corresponding N-OTMS ether. 1,2-Dimethoxyethane (75 ml) was added followed by perfluorooctanesulfonyl fluoride (37.85 ml, 69.04 g, 0.1375 mol) and the resulting biphasic mixture heated to reflux. A solution of triethylamine (3.48 ml, 2.53 g, 25.0 mmol) in 1,2-dimethoxyethane (25 ml) was added to the hot solution and the mixture turned pale orange. The reaction mixture was heated at reflux for 64 h to give a dark brown-black solution. At this stage, TLC showed the presence of the desired product and confirmed complete consumption of the starting alcohol. The reaction mixture was transferred to a 500 ml single neck flask and concentrated in vacuo to give a tan semi-solid which solidified on cooling to room temperature. The crude product (82.10 g) was suspended in hot methanol (200 ml) and heated to dissolve the solid. The resulting solution was cooled to room temperature and on standing for 6 h, a significant amount of crystals were deposited. The crystals were collected by suction filtration, rinsed with ice cold methanol (2×25 ml) and dried in vacuo and temperature for 18 h to give 28.03 g of material. The mother liquor was reduced to half its original volume and cooled in an ice bath to deposit additional solid. The second crystal crop was isolated as described above to give an additional 6.81 g of material. The two crystal crops were combined and purified by dry flash column chromatography using Flash grade silica gel using 50% dichloromethane/50% haxane as eluant. The material was further purified by recrystallization from hexanes. After drying at 50 C. for 24 h, N-[(perfluorooctanesulfonyl)oxy]-5-norbornene-2,3-dicarboximide was isolated as a white crystalline solid.

1. customThe flask was fitted with a condenser, a dropping funnel
2. temperaturea gentle reflux
3. temperatureheated
4. temperaturethe resulting biphasic mixture heated to reflux
5. temperatureThe reaction mixture was heated
6. temperatureat reflux for 64 h
7. customto give a dark brown-black solution

ORD record

ord-e0e4a86628044a1098f28e8714d60b11

Source dataset

uspto-grants-2000_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06048672