Acetic Acid → 2-Chloro-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3-thiazole

Diisopropylamine (0.66 mL, 4.6 mmol) and triisopropylborate (1.26 mL, 5.44 mmol) were dissolved in 52 mL of anhydrous diethyl ether and then cooled to −90° C. n-Butyllithium (2.6 M in toluene, 1.77 mL, 4.6 mmol) was added slowly to the reaction and the mixture was stirred for 30 min. 2-Chlorothiazole (0.5 g, 4.18 mmol) was added and the reaction was allowed to gradually reach room temperature over 3 h. A solution of pinacol (0.69 g, 5.85 mmol) in 5 mL of diethyl ether was added. After 15 min, acetic acid (0.26 mL, 4.6 mmol) was added and the mixture was then filtered through Celite, rinsing with more diethyl ether. The filtrate was evaporated and the residue was distilled using a Kugelrohr apparatus at a temperature of 120-130° C. to give 0.84 g (82%) of 2-chloro-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-thiazole.

1. additionwas added slowly to the reaction
2. waitthe reaction was allowed to gradually reach room temperature over 3 h
3. waitAfter 15 min
4. filtrationthe mixture was then filtered through Celite
5. washrinsing with more diethyl ether
6. customThe filtrate was evaporated
7. distillationthe residue was distilled
8. customat a temperature of 120-130° C.

ORD record

ord-d19d67cfdc5b49bd95451c01c40a3436

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08518945B2