Sodium hydride → HCID 178418385, compound

Temperature

6 °C

This compound was synthesized strictly under dry and inert reaction conditions. The compound 2-(2′-tert-butyl-di-metylsilyloxy-5′-bromomethylphenyl)benzotriazole (2.1 gms, 0.00501 M) was taken in one 25 mL capacity RB and dissolved in 8 mL dry dimethylformamide (DMF) under Argon atmosphere with stirring. In another two-necked RB, 1,2,2,6,6-pentamethyl-4-piperidinol (1.0356 gm, 0.00601 M) and sodium hydride (0.3 gms, 0.01252 M) were taken and dissolved in 6 mL dry DMF with stirring under Argon atmosphere. This reaction mixture was agitated for almost 60 min and then cooled to 4-8° C. To this reaction mixture the contents of the first RB was added gradually over a period of 30-60 min. This reaction mixture was further agitated for 2-4 hrs followed by refluxing the same for a period of 2-4 hrs. The contents of the RB were cooled to room temperature and further agitated for 4-6 hrs at room temperature. The solvent in the RB was evaporated under reduced pressure and the solid mass in the RB was dissolved in 15 mL water and repeatedly extracted with dichloromethane (4×10 mL). Dichloromethane was then evaporated under vacuum at 38° C. over a rotavapor to give pale yellow colored crystalline product 2-[2′-tert-butyldimetylsilyloxy-5′-methyleneoxy((1″, 2″, 2″, 6″, 6″-pentamethyl-4″-piperidinyl) phenyl)benzotriazole. The TLC showed very little amount of unreacted starting material. The crude yield was 2.22 gms (87%). The product was purified by recrystalization technique using an appropriate organic solvent to get (83%) yield of sure product.

1. customThis compound was synthesized strictly
2. customunder dry
3. custominert reaction conditions
4. stirringwith stirring under Argon atmosphere
5. stirringThis reaction mixture was agitated for almost 60 min
6. additionTo this reaction mixture the contents of the first RB was added gradually over a period of 30-60 min
7. stirringThis reaction mixture was further agitated for 2-4 hrs
8. temperatureby refluxing the same for a period of 2-4 hrs
9. temperatureThe contents of the RB were cooled to room temperature
10. stirringfurther agitated for 4-6 hrs at room temperature
11. customThe solvent in the RB was evaporated under reduced pressure
12. dissolutionthe solid mass in the RB was dissolved in 15 mL water
13. extractionrepeatedly extracted with dichloromethane (4×10 mL)
14. customDichloromethane was then evaporated under vacuum at 38° C. over a rotavapor

ORD record

ord-c733190362804109bf547e91ab9604c8

Source dataset

uspto-grants-2002_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06492518B1