Pyridine → HCID 20250426, compound

Temperature

25 °C

To an appropriately sized reaction vessel equipped with a thermowell, Dean Stark trap connected to condenser with a nitrogen inlet, addition funnel, and mechanical stirrer. was charged 2.2 L of cyclohexane followed by dimethylmaleic anhydride (DMMA, 107.8 g, 0.85 mol) and pyridine (3.5 mL, 0.042 mol) with stirring. A slight endotherm was observed (20 to 14° C.) as the dimethylmaleic anhydride dissolved in the cyclohexane. The mixture was warmed to 25° C. and a turbid solution was observed. The addition funnel was charged with 3-aminopropyltriethoxysilane (189.2 g, 200 mL, 0.85 mol) which was added slowly over 15 minutes. An additional 300 mL cyclohexane was added to rinse in the 3-aminopropyltriethoxysilane and the addition funnel was replaced by a stopper. The mixture immediately exothermed to 24° C. and a white turbid solution was observed. The mixture was heated carefully (to avoid excessive foaming) over 30 minutes to reflux. A clear solution was observed at 40° C. and again turned to a white turbid solution at 70° C. The reaction mixture was refluxed for 1 h at 70° C. and aliquot was analyzed and indicated that the reaction was completed (88% product with 11% DMMA and no 3-aminopropyltriethoxysilane). The reaction mixture was cooled to room temperature and the cyclohexane layer decanted to a 5 L flask leaving the white polymeric residue (120 g). The cyclohexane layer was concentrated on the rotary evaporator at 60° C. bath temperature. The residue was transferred to a 500 mL RBF and dried under high vacuum for 2 h at 7° C. bath temperature to give 132 g of crude product as a viscous oil (crude purity 96.5% with 3.2% DMMA). The crude product was further purified via Kugelrohr distillation at 150-170° C. oven temperature under vacuum 0.15-0.2 torr to give 64.4 g (23% yield) of product with 99.7% purity by gas chromatography (GC) as a clear liquid. 1H NMR and mass were consistent with the desired structure. Pot residue was 60.6 g and total polymeric residue was 180.1 g (64%). Data: GC analysis performed on a DB-5MS Column, 25 meters, 0.32 mm ID, 0.52 μm film, heat from 75° C. to 200° C. @15° C./min, then 200° C. to 300° C. hold for 2 min @300° C., Injector temperature: 200° C., Detector temperature: 350° C., Retention time: 9.250 minutes.

1. customTo an appropriately sized reaction vessel equipped with a thermowell, Dean Stark trap
2. additionconnected to condenser with a nitrogen inlet, addition funnel, and mechanical stirrer
3. custom(20 to 14° C.)
4. additionwas added slowly over 15 minutes
5. washto rinse in the 3-aminopropyltriethoxysilane
6. customimmediately exothermed to 24° C.
7. temperatureThe mixture was heated carefully (to avoid excessive foaming) over 30 minutes
8. temperatureto reflux
9. customwas observed at 40° C.
10. customagain turned to a white turbid solution at 70° C
11. temperatureThe reaction mixture was refluxed for 1 h at 70° C.
12. temperatureThe reaction mixture was cooled to room temperature
13. customthe cyclohexane layer decanted to a 5 L flask

ORD record

ord-655aec68ab2f443cbb1ec4119397285b

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09175123B2