600-12-4

Upstream product

• 53993-41-2 (Z)-2-Chloro-but-2-enoic acid 
• 2623-91-8 (R)-2-aminobutyric acid 
• 4170-24-5 2-chlorobutanoic acid 
• 27854-88-2 (R)-1-(4-pyridinyl)ethanol 
• 7623-11-2 2-chlorobutyryl chloride 
• 169221-12-9 (S)-3-hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone 
• 3347-90-8 (2S)-2-hydroxybutanoic acid 
• 1492-24-6 L-2-aminobutyric acid 
• 10026-13-8 phosphorus pentachloride 
• 22038-57-9 (Z) methyl 2-chloro-2-butenoate 
• 692291-17-1 (2S)-2-chlorobutanal 

Downstream Products

• 1263320-65-5 (2R)-2-[4-(5-isopropyl-1,2,4-oxadiazol-3-yl)phenoxy]butyric acid 
• 1263320-66-6 (2R)-2-[4-(5-ethyl-1,2,4-oxadiazol-3-yl)phenoxy]butyric acid 

Relevant academic research and scientific papers

High-quality S - 2 - butylene-chlorohydrin preparation method

The invention relates to a preparation method of high-quality S-2-chlorobutanol. The method comprises the following steps: with L-2-aminobutyric acid prepared by a biological reduction transformation method as a raw material, preparing the S-2-chlorobutanol by adopting a diazotization chlorination method; further esterifying, and reducing with sodium borohydride/titanium tetrachloride, so as to obtain the product. According to the prepared high rotary S-2-chlorobutanol, the EE value is over 99%; and the S-2-chlorobutanol is good in repeatability and stable in process.

Forming Stereogenic Centers in Acyclic Systems from Alkynes

The combined carbometalation/zinc homologation followed by reactions with α-heterosubstituted aldehydes and imines proceed through a chair-like transition structure with the substituent of the incoming aldehyde residue preferentially occupying a pseudo-axial position to avoid the two gauche interactions. The heteroatom in the axial position produces a chelated intermediate (and not a Cornforth-Evans transition structure for α-chloro aldehydes and imines) leading to a face differentiation in the allylation reaction. This method provides access to functionalized products in which three new carbon-carbon bonds and two to three stereogenic centers, including a quaternary one, were created in acyclic systems in a single-pot operation from simple alkynes. All-carbon quaternary stereocenter: The combined carbometalation/zinc homologation of alkynes followed by reactions with α-heterosubstituted aldehydes and imines provides access to functionalized acyclic adducts. These adducts obtained in a single-pot reaction have three new carbon-carbon bonds and two to three stereogenic centers, including a quaternary carbon stereocenter.

Enoate reductase-mediated preparation of methyl (S)-2-bromobutanoate, a useful key intermediate for the synthesis of chiral active pharmaceutical ingredients

Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of α-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.

Amber-woody scent: Alcohols with divergent structure present common olfactory characteristics and sharp enantiomer differentiation

Only one out of the four possible trans isomers of the important perfumery alcohol Norlimbanol (1) possesses a very strong amber-woody smell, the isomer 1A with (1′ R,3S,6'S) absolute configuration. Its enantiomer 1B is almost odorless and devoid of amber-woody character, whereas the diastereoisomers 1C and 1D are considerably weaker and perceptible only by the most-sensitive persons. The same is true for a whole series of perceptual analogs of 1, including β-alkoxy alcohols. These ethers belong to two structural classes: [(2,2,6-trimethylcyclohexyl)oxy]- (see 3, 4, and 16) or {[2-(tert-butyl)cyclohexyl]oxy)alkan-2-ol derivatives (see 19 and 20; Table). A superimposition model allowing for good overlap of the respective hydroxylated side chains offers a tentative explanation for the shared perceptual characteristics of the two classes (Fig. 5). The lipophilic cyclohexane moieties present only a minimal overlap in this model, suggesting that quite larger molecules might possess the same smell. (S)-Configured β-alkoxy alcohols can conveniently be obtained on a larger scale by enantioselective reduction of the corresponding ketones (Scheme 9).

Direct Organocatalytic Asymmetric α-Chlorination of Aldehydes

The direct organocatalytic enantioselective α-chlorination of aldehydes has been developed. The reaction proceeds for a series of different aldehydes with NCS as the chlorine source using easily available catalysts such as L-proline amide and (2R,5R)-diphenylpyrrolidine. The α-chloro aldehydes are obtained in up to 99% yield and up to 95% ee. The synthetic utility of the enantioselective α-chlorination of aldehydes is demonstrated by transformation of the α-chloro aldehydes to the corresponding α-chloro alcohols (>90% yield) by standard reduction and further transformation to both a terminal epoxide and amino alcohol, both obtained without loss of optical purity. Oxidation of the α-chloro aldehydes followed by esterification gave optically active α-chloro esters without loss of optical purity. It is demonstrated that these optically active α-chloro esters can be converted into nonproteinogenic amino acids in overall high yields, maintaining the enantiomeric excess obtained in the catalytic enantioselective α-chlorination step. Copyright

(R)- and (S)-3-hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone as chiral auxiliaries in the enantioselective preparation of α-aryloxypropanoic acid herbicides and α-chlorocarboxylic acids

rac-α-Chlorocarboxylic acids, rac-9a-e, were formally deracemized by reaction of the corresponding acyl chlorides with the chiral auxiliaries (R)- and (S)-3-hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone, (R)- and (S)-4, followed by mild alkaline hydrolysis. The highest o.p. (99%) was obtained in the case of (S)-α-chloropropanoic acid, a known precursor for the synthesis of (R)-α-aryloxypropanoic acid herbicides such as dichlorprop-P, (R)-3a, or mecoprop-P, (R)-3b, which, together with their enantiomers, were also obtained in moderate e.e.s by dynamic kinetic resolution from (αRS,3S)-4,4- dimethyl-2-oxo-l-phenylpyrrolidin-3-yl α-bromopropanoate, (αRS,3S)-6, by reaction with the corresponding phenoxide followed by mild acid hydrolysis.

Cephalosporin compounds

The present invention relates to novel cephalosporin compounds, pharmaceutically acceptable non-toxic salts, physiologically hydrolyzable esters, hydrates and solvates and isomers thereof which possess potent and broad antibacterial activities. The compounds of the present invention have a (4-amino-1-substituted-alkapyrimidinium-4-yl)thiomethyl group in 3-position of the cephem nucleus and is specifically represented by the following formula(I): STR1 wherein: R 1 is a hydrogen atom or a C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl or --C(R A)(R B)COOH group wherein R A and R B are independently a hydrogen atom or a C 1-4 alkyl group, or form a C 3-7 cycloalkyl group together with the carbon atom to which they are attached;R 2 is an unsubstituted or substituted amino, C 1-4 alkyl or C 3-7 cycloalkyl group; andn is an integer ranging from 2 to 7.

Cephalosporin compounds and processes for the preparation thereof

The present invention relates to a cephalosporin compound including the pharmaceutically acceptable non-toxic salts, physiologically hydrolyzable esters, hydrates and solvates thereof of the formula(I) and its isomers: ψψ ψwherein: ψ R1 isa C1-4 alkyl, C3-4 alkenyl, C3-4 alkynyl or -C(Ra)(Rb)-COOH wherein Ra and Rb are, independently of each other, a hydrogen or a C1-4 alkyl group, respectively, or jointly form a C3-7 cycloalkyl group together with the carbon atoms to which they are attached; Ry isa hydrogen or an amino which may be substituted or unsubstituted, alkoxy or heterocyclic group which is linked with a nitrogen atom; R3 isa hydrogen or a C1-4 alkyl, amino, aminomethyl, hydroxy, hydroxymethyl, carboxy or carboxymethyl group; R4 isa hydrogen or a C1-4 alkyl, amino, hydroxy, hydroxyalkl, acetamide, carboxyalkyl or sulfonylethyl group; R5 isa hydrogen or a C1-4 alkyl, amino, carboxy, carboxyalkyl or hydroxy group; and Q and T areindependently CH or N, provided that Ry is an amino group when T is N. ψψ

Novel cephalosporin compounds and processes for the preparation thereof

The present invention relates to novel cephalosporin compounds, pharmaceutically acceptable non-toxic salts, physiologically hydrolyzable esters, hydrates and solvates and isomers thereof which possess potent and broad antibacterial activities. The compounds of the present invention have a (1,5,6-substituted-4-aminopyrimidinium-2-yl)thiomethyl group in 3-position of the cephem nucleus and is specifically represented by the following formula(I): ψψψ

Novel cephalosporin compounds

The present invention relates to novel cephalosporin compounds, pharmaceutically acceptable non-toxic salts, physiologically hydrolyzable esters, hydrates and solvates and isomers thereof which possess potent and broad antibacterial activities. The compounds of the present invention have a (4-amino-1-substituted-alkapyrimidinium-4-yl)thiomethyl group in 3-position of the cephem nucleus and is specifically represented by the following formula(I): wherein: R1 isa hydrogen atom or, a C1 4 alkyl, C2 4 alkenyl, C2 4 alkynyl or -C(RA)(RB)COOH group wherein RAand RBare independently a hydrogen atom or a C1 4 alkyl group, or form a C3 7 cycloalkyl group together with the carbon atom to which they are attached; R2 isan unsubstituted or substituted amino, C1 4 alkyl or C3 7 cycloalkyl group; and n isan integer ranging from 2 to 7.