Реакция #10490

Уравнение реакции

5-Bromo-2-methyl-benzothiazole

NH4Cl

LiTMP

n-BuLi

para-formaldehyde

→

2-(5-Bromo-benzothiazol-2-yl)-ethanol

Растворители

THF

Условия реакции

Обработка

1. 1
   workup.STIRRINGafter stirring for 4 hours at −78° C.
2. 2
   workup.STIRRINGwhile stirring rapidly
3. 3
   Экстракцияthe reaction was extracted with CH2Cl2
4. 4
   Другоеdried
5. 5
   Концентрированиеconcentrated in vacuo
6. 6
   Другоеto give crude product, 1.02 g
7. 7
   ДругоеThe crude product was purified by flash chromatography
8. 8
   Промывкаeluting with CH2Cl2
9. 9
   Промывкаwith 20% MeOH/CH2Cl2 to elute the product

Методика

To a dry 100 mL flask, 2,2,6′,6′-tetra-methyl piperidine (0.56 g, 4 mmol) and 6 mL of THF was added and cooled to −78° C. Then n-BuLi (1.5 mL, 2.5M) was added rapidly, and the mixture of LiTMP was stirred for 3 hr. 5-Bromo-2-methyl-benzothiazole (0.75 g, 3.3 mmol) was added in solid form in to the reaction at −78° C., and after stirring for 4 hours at −78° C., 6 equivalents of para-formaldehyde was added to the reaction while stirring rapidly. The reaction was worked up by addition of sat. NH4Cl solution, and the reaction was extracted with CH2Cl2 dried, and concentrated in vacuo to give crude product, 1.02 g. The crude product was purified by flash chromatography, eluting with CH2Cl2, then with 20% MeOH/CH2Cl2 to elute the product. 1H NMR (400 MHz, CDCl3) d ppm 3.32 (t, J=5.76 Hz, 2 H) 4.11 (q, J=5.95 Hz, 2 H) 7.48 (dd, J=8.51, 1.92 Hz, 1 H) 7.70 (d, J=8.51 Hz, 1 H) 8.11 (d, J=1.92 Hz, 1 H)

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