50293-91-9

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• 54208-72-9 2-(tert-butylamino)-1-(2,2-dimethyl-4H-benzo[d][1,3]dioxan-6-yl)ethanol 
• 39235-58-0 4-hydroxy-3-hydroxymethylacetophenone 
• 54030-34-1 1-(2,2-dimethyl-4H-benzo[d][1,3]dioxan-6-yl)ethanone 
• 34391-04-3 Levalbuterol 
• 174607-68-2 (R)-1-[4-benzyloxy-3-hydroxymethylphenyl]-2-tert-butylaminoethanol 
• 238762-31-7 (R)-2-(N-tert-butylamino)-1-(2,2-dimethyl-4H-benzo[3,4-e]1,3-dioxin-6-yl)ethanol 
• 90-02-8 salicylaldehyde 
• 115787-50-3 5-(2-bromoacetyl)-2-hydroxybenzaldehyde 

Relevant academic research and scientific papers

Salbutamol hydrochloride preparation method suitable for industrial production

The invention discloses a salbutamol hydrochloride preparation method suitable for industrial production. 4-hydroxy-3-hydroxymethylacetophenone used as an initial raw material undergoes epoxy protection, oxidation, reductive amination and deprotection salification to obtain salbutamol hydrochloride. The method has the advantages of no bromination process in the whole reaction process, avoidance ofuse of high-risk reagents, small environmental pollution, low device requirements, simplicity in operation, mild reaction conditions, simplified steps, low production cost, and suitability for industrial production.

Levalbuterol intermediate and synthetic method of levalbuterol hydrochloride

The invention provides a levalbuterol intermediate and a levalbuterol hydrochloride synthesis method, and relates to a levalbuterol intermediate and a method for preparing levalbuterol hydrochloride from the intermediate. The method comprises steps as follows: 2-halogenate-1-(2,2-dimelthyl-4-hydrogen-benzo [d][1,3] dioxane)-butanone and organic amine have a Hoffman alkylation reaction to prepare a compound in the formula 2, the structural formula of the compound is shown in the specification, and the compound in the formula 2 is subjected to a reduction reaction, optically pure organic acid resolution and deprotection by hydrochloric acid to obtain levalbuterol hydrochloride. The method does not need processes of protection or deprotection and the like of hydroxyl groups on a benzene ring, protection, deprotection and purification processes are reduced, the synthesis route is short, operation is simple, meanwhile, borane-thioether does not need to be used as a reduction agent, and safety and environmental protection are realized.

(R)- albuterol hydrochloride asymmetric preparation method (by machine translation)

The present invention relates to a high-efficient chiral catalyst synthesis of (R)- albuterol hydrochloride the asymmetric synthesis of the new method, the synthesis step includes: 1) salicylaldehyde with a halo of acetyl halogen crafts acylation reaction halo; 2) obtained after the the halogenated ketone uses unclebutylamine amine solution obtained after hydrolysis to the protection of the salicylaldehyde aminoketone; 3) this aminoketone in chiral amino alcohol derivative of the chiral borane the presence of a catalyst, is reduced to (R)- albuterol crude product, then the purified hydrochloric salt to obtain the high purity of the (R)- albuterol hydrochloride. (by machine translation)

Preparation method of leverbuterol and its salt

The invention provides a method for cheap and effective preparation of leverbuterol in industry. The method consists of: taking protected 4-hydroxy-3-hydroxymethyl acetophenone as the raw material to react with bromine to generate acyl or alkyl protected 4-hydroxy-3-hydroxymethyl bromoacetophenone, under in the presence of (1R, 2S)-(+)-indanol as a catalyst, using borane to conduct chiral reduction on carbonyl in the structural formula to obtain R configuration acyl or alkyl protected 4-hydroxy-3-hydroxymethyl alpha bromo phenethyl alcohol, then carrying out reaction with tert-butylamine to generate acyl or alkyl protected 4-hydroxy-3-hydroxymethyl phenylaminoethanol, and finally removing the acyl protecting group to obtain leverbuterol free alkali, and letting the free alkali and acid form a salt. The finished product has optical purity up to 99.9%, and no other chiral resolution way is needed for purification.

PROCESS FOR THE PREPARATION OF OPTICALLY PURE R (-) SALBUTAMOL AND ITS PHARMACEUTICALLY ACCEPTABLE SALTS

A process for the preparation of optically pure R (?) salbutamol of formula (6) and its pharmaceutically acceptable salts by using a (+) 4-nitro tartranilic acid as the resolving agent and a binary solvent system comprising alkyl acetate and C1 /sub

A PROCESS FOR THE PREPARATION OF OPTICALLY PURE R (-) SALBUTAMOL AND ITS PHARMACEUTICALLY ACCEPTABLE SALTS

A process for the preparation of optically pure R (-) salbutamol of formula (6) and its pharmaceutically acceptable salts by using a (+) 4-nitro tartranilic acid as the resolving agent and a binary solvent system comprising alkyl acetate and C1 to C4 branched or normal chain alcohol for dissolution of the racemic mixture and resolving agent and purification of the 4-nitro tartranilic acid salt of R (-) salbutamol. 4-nitro tartranilic acid salt of R (-) salbutamol is converted into formic acid salt of R(-) 4-benzyl salbutamol followed by basification and debenzylation to form optically pure R(-) salbutamol. Optically pure (R) -salbutamol is obtained in good yield and high purity. The optically pure R(-) salbutamol is optionally converted into pharmaceutically acceptable salts.

Synthesis of the Adrenergic Bronchodilators (R)-Terbutalinel and (R)-Salbutamol from (R)-Cyanohydrins

Stereoselective syntheses of (R)-terbutaline and (R)-salbutamol acetal, which are important bronchodilators, starting from O-protected (R)-cyanohydrins are described. (R)-Terbutaline hydrochloride (R)-9·HCl is obtained in an overall yield of 44% with >98% ee from the O-bisallyl-protected cyanohydrin (R)-4k via a Ritter N-tertiary butylation to the amide (R)-6a, hydrogenation to the amino alcohol (R)-7a, and deprotection of the hydroxyl functions. (R)-Salbutamol acetals (R)-7b,c can be obtained from the corresponding O-protected (R)-cyanohydrins either via the route described for (R)-terbutaline or via selective hydrogenation of the protected cyanohydrin (R)-11 to the imino derivative, transimination with tert-butylamine, followed by hydrogenation with NaBH4 to give the 2-amino alcohol derivative (R)-12. Desilylation of (A)-12 to (R)-7c is performed with LiAlH4. Hydrolytic cleavage of the acetals (A)-7b and c to (R)-salbutamol was not yet possible without racemization.

Enantioselective preparation of optically pure albuterol

The invention relates to a method for producing albuterol by the resolution of a mixture of enantiomers of methyl 5-[2-[(1,1-dimethylethyl)amino]-1-hydroxyethyl]-2-(phenylmethoxy)benzoate or α-[[(1,1-dimethylethyl)amino]methyl]-4-(phenylmethoxy)-1,3-benzenedimethanol using a chiral acid such as (+/-) di-toluoyltartaric acid or (+/-) di-benzoyltartaric acid.