Diisopropylamine → HCID 21865357, compound

Participants

Reaction Conditions

Reaction Steps

2.1 ml (15 mmol) diisopropylamine were dissolved in 70 ml dry tetrahydrofuran and cooled to −75° C. and 9.4 ml of a solution of n-butyllithium (1.6 M, 15 mmol) were added over a period of 10 minutes. After stirring for 15 minutes at −75° C. a solution of 1.69 g (12 mmol) 2-methylthio-4-methylpyrimidine in 5 ml dry tetrahydrofuran was added within 10 minutes at −75° C. and the mixture was stirred for additional 15 minutes. Then a solution of 2.73 g (7 mmol) B3 (70% purity) in 5 ml dry tetrahydrofuran was added within 10 minutes at −75° C. The mixture was stirred for one hour at −75° C. and then allowed to warm up to room temperature and finally poured on 100 ml ethyl acetate/water (1:1). The aqueous layer was extracted with 50 ml ethyl acetate and the combined organic layers were dried over sodium sulphate. Removal of the solvent in vacuo and column chromatography on Silica (n-heptane/ethyl acetate 3:1) yielded 1.52 g (62%) C1. (keto-enole ratio measured by NMR in CDCl3 at 400 MHz is about 30:70).

Provenance & Evidence