Dimethylmaleic anhydride → HCID 66606590, compound

Temperature

25 °C

DMMIEtNB: A 3 L, 4 neck RBF was equipped with a thermowell, Dean Stark trap connected to condenser with a nitrogen inlet, addition funnel and mechanical stirrer. The RBF was charged with 600 mL toluene followed by dimethylmaleic anhydride (DMMA, 92 g, 0.73 mol) with stirring. The mixture cooled to 14° C. as the dimethylmaleic anhydride dissolved in the toluene. The mixture was warmed to 25° C. to clear the solution. The addition funnel was charged with aminoethylnorbornene (104 g, 0.73 mol, 96.4% pure) in 100 mL toluene and added drop wise over 15 minutes. An additional 130 mL toluene was added to rinse in the aminoethylnorbornene and the addition funnel was replaced by a stopper. The mixture immediately exothermed to 50° C. and a white thick precipitate was observed. The mixture was heated carefully (to avoid excessive foaming) to reflux over 30 minutes and refluxed for 2 hours. A clear solution was observed and 13.1 mL water (99.5% of theoretical) was collected in the Dean Stark trap. GC analysis revealed the reaction was complete (94.9% product with 1.8% DCPD and 1.7% unknown impurity at 7.8 minute). The reaction mixture was cooled to room temperature and transferred to 5 L flask and concentrated on the rotary evaporator. The crude product was further dried under high vacuum (0.94 torr) at 75° C. bath temperature on the rotary evaporator for 5 h and gave 179 g of crude product as dark orange color viscous oil. GC analysis indicated the purity of crude product after drying under high vacuum was 97.4% with 0.3% DCPD and 1.8% unknown impurity. The 179 g of crude product was adsorbed in 179 g of silica gel and chromatographed over 500 g of silica gel eluting with heptane (8 L), 2% EtOAc in heptane (2 L), 2.5% EtOAc in heptane (2 L), 3% EtOAc in heptane (4 L) and 5% EtOAc in heptane (1 L). The concentrated purified fractions yielded 164 g of product as colorless viscous oil (91% yield) with 99.8% purity by GC. 1H NMR and mass spectrum were consistent with the structure. Data: GC analysis done on a DB5 Column, 30 meters, 0.32 mm ID, 0.25 μm film, 75° C. to 300° C. at 15° C./min, 2 min hold at 300° C., Injector temperature: 275° C., Detector temperature: 350° C., Retention time: 11.893 minute.

1. customDMMIEtNB: A 3 L, 4 neck RBF was equipped with a thermowell, Dean Stark trap
2. additionconnected to condenser with a nitrogen inlet, addition funnel and mechanical stirrer
3. additionadded drop wise over 15 minutes
4. washto rinse in the aminoethylnorbornene
5. customimmediately exothermed to 50° C.
6. temperatureThe mixture was heated carefully (to avoid excessive foaming)
7. temperatureto reflux over 30 minutes
8. temperaturerefluxed for 2 hours
9. custom13.1 mL water (99.5% of theoretical) was collected in the Dean Stark trap
10. custom(94.9% product with 1.8% DCPD and 1.7% unknown impurity at 7.8 minute)
11. temperatureThe reaction mixture was cooled to room temperature
12. customtransferred to 5 L flask
13. concentrationconcentrated on the rotary evaporator
14. dry with materialThe crude product was further dried under high vacuum (0.94 torr) at 75° C. bath temperature
15. customon the rotary evaporator for 5 h
16. customgave 179 g of crude product as dark orange color viscous oil
17. customafter drying under high vacuum
18. customchromatographed over 500 g of silica gel eluting with heptane (8 L), 2% EtOAc in heptane (2 L), 2.5% EtOAc in heptane (2 L)
19. customThe concentrated purified fractions

ORD record

ord-8961da440eb5495e914f007519867b44

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09175123B2