Methanamine, N-methoxy-, hydrochloride (1:1) → 4-Benzyl-7,7-dimethyl-5-phenyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-3-carboxylic acid methoxy-methyl-amide

Participants

Reaction Conditions

Reaction Steps

To a 5 mL NMP solution containing 0.72 g (1.99 mmol) of 2 was added 0.91 g (2.39 mmol) of O-7-azabenzotriazolo-1-yl)-N,N,N′,N′-tetramethyluroniumhexafluorophosphate (HATU) and 0.416 mL (2.39 mmol) of diisopropylethylamine. After stirring for 30 min, 0.233 g (2.39 mmol) of O,N-dimethyl-hydroxylamine hydrochloride was added and the reaction heated to 50° C. After 1 h, the reaction mixture was poured into water and extracted with AcOEt. The combined organic layers were washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo to give a crude oil. Purification of this oil by flash chromatography eluting with a 60 to 50% hexanes/AcOEt gradient gave 0.65 g (81%) of the title compound as a light golden colored solid. 1H NMR (CDCl3) δ 1.37 (s, 3H), 1.56 (s, 3H), 2.06-2.16 (m, 2H), 3.25 (s, 3H), 3.49 (s, 3H), 3.90 (d, J=16.0 Hz, 1H), 4.45 (dd, J=5.1, 11.3 Hz, 1H), 5.06 (d, J=16.2 Hz, 1H), 6.98 (dd, J=1.8, 6.1 Hz, 2H), 7.20-7.24 (m, 3H), 7.30-7.34 (m, 1H), 7.37-7.41 (m, 4H), 7.74 (s, 1H). MS Calcd.: 404. Found: 405 (M+H).

Provenance & Evidence