Chen, Yantao published the artcileSynthesis of Enantiomerically Pure 2-Heteroaromatic-Substituted 1,2-Amino Alcohols from Chiral tert-Butanesulfinyl Aldimines, Name: 1-Methylpyrazole, the publication is Synthesis (2015), 47(5), 679-691, database is CAplus.
Nine R/S pairs of 2-heteroaromatic-substituted 1,2-amino alcs. were synthesized through 1,2-nucleophilic addition between chiral N-(tert-butylsulfinyl)imines and heteroaromatic carbanions. In most cases, the RS-isomer of N-(tert-butylsulfinyl)imines afforded the (R)-amino alc. from deprotection of the major diastereomer, and (S/S)-imines afforded the (S)-product. In general, this procedure allows for the preparation of a variety of enantiomeric pairs of 2-heteroaromatic-substituted 1,2-amino alcs. on a practical scale (>10 g) in two steps in good yields. Aldimines were prepared from [S(S)]-2-methyl-2-propanesulfinamide and [S(R)]-2-methyl-2-propanesulfinamide. The synthesis of the target compounds was achieved by a reaction of , [S(S)]-N-[2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]ethylidene]-2-methyl-2-propanesulfinamide (chiral auxiliary, tert-butanesulfinyl aldimine) and [S(R)]-N-[2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]ethylidene]-2-methyl-2-propanesulfinamide (chiral auxiliary) with 5-bromo-2-methoxypyridine, 3-bromo-1-methyl-1H-pyrazole, 1-methyl-1H-imidazole, 2-chloro-1-methyl-1H-imidazole, 4-bromo-2-methoxypyridine, pyrazine, 1-methyl-1H-pyrazole, 1,4-dimethyl-1H-pyrazole, 1-methyl-1H-1,2,4-triazole. Key intermediates included [S(S)]-N-[(1S)-2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-(1-methyl-1H-1,2,4-triazol-5-yl)ethyl]-2-methyl-2-propanesulfinamide and a diastereomer, [S(R)]-N-[(1S)-2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-(1-methyl-1H-1,2,4-triazol-5-yl)ethyl]-2-methyl-2-propanesulfinamide. Chiral β-(amino)alkanol derivatives included β-amino-1-methyl-1H-1,2,4-triazole-5-ethanol and (βS)-β-amino-6-methoxy-3-pyridineethanol, (βR)-β-amino-1-methyl-1H-imidazole-1-ethanol, (βS)-β-amino-1-pyrazineethanol, (βR)-β-amino-1-pyrazineethanol.
Synthesis published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Name: 1-Methylpyrazole.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics