Hydrazine hydrate (1:1) → 4-p-tolylmethanesulfonyl-2H-pyrazol-3-ylamine

HRID 2108577Notes

Reaction equation

HRID 2108577 reaction equation
C(N1C(C2C=CC=CC=2)CC(C)(C)[N:10]2[N:22]=CC(C(=O)CC3C=CC(C)=CC=3)=C12)C1C=CC=CC=1.C(O[CH:38]=[C:39]([S:42]([CH2:45][C:46]1[CH:51]=[CH:50][C:49]([CH3:52])=[CH:48][CH:47]=1)(=[O:44])=[O:43])[C:40]#[N:41])C.O.NN>C(O)C>[C:49]1([CH3:52])[CH:50]=[CH:51][C:46]([CH2:45][S:42]([C:39]2[CH:38]=[N:22][NH:10][C:40]=2[NH2:41])(=[O:44])=[O:43])=[CH:47][CH:48]=1

Participants

5

Procedure

7,7-Dimethyl-3-(4-methylbenzyl)sulfonyl)-5-phenyl-4,7-dihydropyrazolo[1,5-a]pyrimidine (4): A slurry of 1.9 g (7.2 mmol) of 3 in 25 mL of ethanol was treated with 0.38 mL (7.9 mmol) of hydrazine monohydrate and heated to reflux for 3 h. The reaction was concentrated in vacuo to give crude 4-p-tolylmethanesulfonyl-2H-pyrazol-3-ylamine as a tan solid. The crude pyrazole, 1.3 g (7.9 mmol) of 3-methyl-1-phenyl-but-2-en-1-one and 2.8 mL (36 mmol) of trifluoroacetic acid was dissolved in 25 mL of 2-methoxyethanol and heated to reflux for 3 days. The reaction was then cooled to room temperature, concentrated in vacuo and dissolved in AcOEt. This solution was washed successively with saturated sodium bicarbonate, water and brine before being dried over sodium sulfate. The solution was filtered, concentrated in vacuo and the resulting crude material was purified by flash chromatography eluting with a 75 to 33% hexanes/AcOEt gradient to give 1.25 g (44%) of the title compound as a powder. 1H NMR (CDCl3) δ 1.67 (s, 6H), 2.13 (s, 3H), 4.26 (s, 2H), 4.81 (d, J=2.0 Hz, 1H), 6.39 (s, 1H), 7.05 (dd, J=8.0, 18.5 Hz, 4H), 7.20 (dd, J=3.7, 7.4 Hz, 2H), 7.36-7.39 (m, 3H), 7.52 (s, 1H). MS Calcd.: 393. Found: 394 (M+H).

Workup

  1. temperatureheated
  2. temperatureto reflux for 3 h
  3. concentrationThe reaction was concentrated in vacuo

Sources & evidence

ORD record
ord-4158a306ba164a7a84f11b57fc8399d0
Source dataset
uspto-grants-2009_04
Patent number
US07514441B2

Reaction notes

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