Ethyl 4-isopropylthiazole-2-carboxylate → 4-Cyclobutylthiazole-2-carboxylic acid ethyl ester

Reaction equation

Br[CH:2]1[CH2:5][CH2:4][C:3]1=[CH:6][CH:7]=O.C(OCC)(=S)C(N)=O.C(C1[N:21]=[C:22]([C:25]([O:27][CH2:28][CH3:29])=[O:26])[S:23]C=1)(C)C>>[CH2:28]([O:27][C:25]([C:22]1[S:23][CH:7]=[C:6]([CH:3]2[CH2:2][CH2:5][CH2:4]2)[N:21]=1)=[O:26])[CH3:29]

Participants

Reactant 3

HCID 10821861Ethyl 4-isopropylthiazole-2-carboxylate

HCID 216137632-ethoxy-2-thioxoAcetamide

HCID 866464072-Bromo-1-cyclobutylylethanone

Product 1

HCID 537082264-Cyclobutylthiazole-2-carboxylic acid ethyl esterYield 64%

Procedure

4-Cyclobutylthiazole-2-carboxylic acid ethyl ester 265b was synthesized from compound 264b (23.87 g, 1 eq.) and ethyl thiooxamate (21.41 g, 1 eq.) as a yellow oil in 64% yield, following the procedure as described for compound 212. 1H NMR (DMSO-d6, 400 MHz): δ (ppm) 1.32 (t, J=7.12 Hz, 3H), 1.82-1.89 (m, 1H), 1.92-2.02 (m, 1H), 2.15-2.33 (m, 4H), 3.65-3.74 (m, 1H), 4.36 (q, J=7.12 Hz, 2H), 7.76 (d, J=0.64 Hz, 1H); MS (ESI, EI+): m/z=212 (MH+).