Ammonium Chloride → 7-(1-Ethyl-propyl)-3-(2-iodo-thiazol-5-yl)-2,5-dimethyl-pyrazolo[1,5-a]pyrimidine

Participants

Reaction Conditions

Reaction Steps

Add a freshly prepared solution of lithium di-i-propylamide (150 ml; 62 4 mmol, 0.6 M in THF) to a mixture of 7-(1-ethyl-propyl)-2,5-dimethyl-3-thiazol-5-yl-pyrazolo[1,5-a]pyrimidine, (17.8 g, 62 4 mmol) in THF (100 mL) at −78° C. under a nitrogen atmosphere, keeping the temperature below −74° C. during the addition. Stir the mixture at −78° C. for one hour and then add a solution of N-iodosuccinimide (15 g, 63 mmol) in THF (100 mL) keeping temperature below −74° C. Warm the reaction gradually to 22° C. and then add a 10% aqueous solution of ammonium chloride (300 mL). Separate the organic layer and wash the aqueous layer with methyl-t-butyl ether (2×200 mL). Combine the organic layers, dry over sodium sulfate, filter, and evaporate the solvent. Purify the resulting residue by silica gel chromatography, eluting with hexanes/acetone (5/1) to afford the title compound (15 g, 60%). ES/MS m/z 427 (M+1)+.

Provenance & Evidence