Hydrochloric Acid → Ethyl 2-chloro-1,3-thiazole-5-carboxylate

To a solution of tert-butyl nitrite (9.3 g, 90 mmol) and cupric chloride (9.7 g, 72 mmol) in 150 mL of acetonitrile at 65° C. was added portionwise ethyl 2-aminothiazole-5-carboxylate (10.3 g, 60 mmol) (prepared by the method of Dann, O. Chem Ber 76 419 (1943)) resulting in vigorous gas evolution. After the addition was complete, the solution was stirred until gas evolution ceased (30 minutes). The solution was cooled and poured into 250 mL of cold 20% v/v aqueous HCl. The aqueous solution was extracted 3 times with 200 mL of EtOAc. The organics were combined, washed once with 100 mL of 20% aqueous HCl and 2 times with 100 mL saturated brine and dried over magnesium sulfate. Concentration in vacuo gave 11.1 g (97% yield) of a brown oil which required no purification.

1. customprepared by the method of Dann
2. customChem Ber 76 419 (1943)) resulting in vigorous gas evolution
3. additionAfter the addition
4. custom(30 minutes)
5. temperatureThe solution was cooled
6. extractionThe aqueous solution was extracted 3 times with 200 mL of EtOAc
7. washwashed once with 100 mL of 20% aqueous HCl and 2 times with 100 mL saturated brine
8. dry with materialdried over magnesium sulfate
9. concentrationConcentration in vacuo

ORD-Eintrag

ord-794b9b12ea8b4ac28c3dcb73f9d02682

Quelldatensatz

uspto-grants-1994_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05326776