5-TERT-BUTYL-1,3,4-THIADIAZOLE-2-CARBOXYLIC ACID ETHYL ESTER synthesis

Yield:1256240-31-9 100%

Reaction Conditions:

Stage #1: ethyl 5-tert-butyl-1,3,4-thiadiazole-2-carboxylatewith methanol;sodium tetrahydroborate at 20; for 1 h;
Stage #2: with hydrogenchloride in water at 20; pH=7; for 1 h;

Steps:

3.1

1 g (4.67 mmol) of ethyl 5-tert-butyl-1,3,4-thiadiazole-2-carboxylate is dissolved in 45 mL of methanol and 0.353 g (9.33 mmol) of sodium borohydride is added portionwise, with stirring, at room temperature. The medium is stirred for 1 hour at room temperature and then concentrated under vacuum. The residue obtained is taken up in aqueous solution saturated with sodium chloride. The aqueous solution is brought to ph 7 by slowly adding, with stirring, aqueous 1N hydrochloric acid solution. After stirring for 1 hour at room temperature, the aqueous phase is extracted three times with dichloromethane and the combined organic phases are then washed once with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated to dryness. 0.802 g (100%) of the expected product is obtained in the form of an oil.LC- MS: M+H=173¹H NMR (CDCl₃) δ (ppm) : 5.10 (d, 2H); 4.60 (t, 1H); 1.65 (s, 9H).

References:

US2012/95040,2012,A1 Location in patent:Page/Page column 8