Asymmetric process for preparing florfenicol, thiamphenicol
chloramphenicol and oxazoline intermediates
    2.
    发明授权
    Asymmetric process for preparing florfenicol, thiamphenicol chloramphenicol and oxazoline intermediates 失效
    制备氟苯尼考,甲砜霉素氯霉素和恶唑啉中间体的不对称方法

    公开(公告)号:US5352832A

    公开(公告)日:1994-10-04

    申请号:US993932

    申请日:1992-12-18

    摘要: The present invention comprises a process for the asymmetric synthesis of florfenicol, thiamphenicol or chloramphenicol, from a derivative of trans-cinnamic acid, comprising the steps:(a) converting the acid to an acid chloride using a chlorinating agent, and reducing the acid chloride to a trans allylic alcohol with a reducing agent;(b) asymmetrically epoxidizing the allylic alcohol of step (a), by reacting with t-butylhydroperoxide in the presence of a chiral epoxidation catalyst prepared from titanium (IV) isopropoxide and L-diisopropyltartaric acid, to form a chiral epoxide;(c) regioselectively opening the epoxide of step (b) by sequentially treating with sodium hydride, zinc chloride and dichloroacetonitrile to form an oxazoline;(d) stereoselective inversion/isomerization of the oxazoline of step (c) by sequentially treating with: (i) a lower alkylsulfonyl chloride and a tertiary amine base; (ii) sulfuric acid and water; (iii) an alkali metal hydroxide; to form an oxazoline;(e) optionally treating the oxazoline of step (d) with a fluorinating agent, for preparing florfenicol, then hydrolyzing with acid.In an alternative embodiment, the present invention comprises a process for isomerizing of the S,S-isomer of florfenicol to the R,S-isomer (I) by sequentially treating with: (i) a lower alkylsulfonyl chloride and a tertiary amine base; (ii) sulfuric acid and water; (iii) an alkali metal hydroxide.The present invention further comprises a process for regioselectively opening an epoxide to form a threo-oxazoline.

    摘要翻译: 本发明包括由反式肉桂酸衍生物不对称合成氟苯尼考,甲砜霉素或氯霉素的方法,包括以下步骤:(a)使用氯化剂将酸转化为酰氯,并将酰氯还原 与还原剂的反式烯丙醇; (b)通过与叔丁基过氧化氢在由异丙醇钛(Ⅳ)和L-二异丙基酒石酸制备的手性环氧化催化剂存在下反应形成手性环氧化物,使步骤(a)的烯丙醇不对称环氧化; (c)通过依次用氢化钠,氯化锌和二氯乙腈处理以形成恶唑啉,选择性地打开步骤(b)的环氧化物; (d)通过以下步骤依次处理步骤(c)的恶唑啉的立体选择性反转/异构化:(i)低级烷基磺酰氯和叔胺碱; (ii)硫酸和水; (iii)碱金属氢氧化物; 形成恶唑啉; (e)任选用氟化剂处理步骤(d)的恶唑啉,制备氟苯尼考,然后用酸水解。 在一个替代实施方案中,本发明包括通过以下步骤:(i)低级烷基磺酰氯和叔胺碱使氟苯尼考的​​S,S-异构体异构化成R,S-异构体(I)的方法。 (ii)硫酸和水; (iii)碱金属氢氧化物。 本发明还包括区域选择性地打开环氧化物以形成苏氨恶唑啉的方法。

    Synthesis of intermediates useful in preparing tricyclic compounds
    5.
    发明授权
    Synthesis of intermediates useful in preparing tricyclic compounds 失效
    可用于制备三环化合物的中间体的合成

    公开(公告)号:US5998620A

    公开(公告)日:1999-12-07

    申请号:US45803

    申请日:1998-03-23

    CPC分类号: C07D401/04 C07D221/16

    摘要: The invention relates to a process for preparing a compound of the formula ##STR1## comprising reacting a bromo-substituted pyridine with an amine of the formula NHR.sup.5 R.sup.6, reacting the resulting amide with an iodo-halomethyl-substituted compound and cyclizing the resultant product, wherein R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined in the specification; also claimed are a compound of the formula ##STR2## and a process for preparing it from the corresponding halo-substituted benzoic acid.

    摘要翻译: 本发明涉及一种制备下式化合物的方法,其中包括使溴取代的吡啶与式NHR 5 R 6的胺反应,使得到的酰胺与碘代卤代甲基取代的化合物反应,并使得到的产物环化,其中R,R 1 R2,R3和R4如说明书中所定义; 还要求的是下式的化合物及其由相应的卤代取代的苯甲酸制备的方法。

    3-hydroxy gamma-lactone based enantioselective synthesis of azetidinones
    6.
    发明授权
    3-hydroxy gamma-lactone based enantioselective synthesis of azetidinones 失效
    基于3-羟基γ-内酯的对映选择性合成氮杂环丁酮

    公开(公告)号:US5886171A

    公开(公告)日:1999-03-23

    申请号:US864529

    申请日:1997-05-28

    IPC分类号: C07D205/08

    CPC分类号: C07D205/08

    摘要: The invention relates to a process for producing a compound of the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in the specification, which comprises the steps of: (a) reacting a lactone with an imine to obtain a chiral diol of the formula IV; (b) oxidizing the diol to obtain an aldehyde of formula V; (c) condensing the aldehyde with an enolether followed by dehydration to obtain a compound of formula VI; (d) hydrogenating the compound of formula VI to obtain a ketone of formula VII; and (e) chirally catalytically reducing the ketone, wherein steps (b)-(d) are shown in the following reaction scheme: ##STR2##

    摘要翻译: 本发明涉及一种制备下式化合物的方法,其中R 1,R 2和R 3如说明书中所定义,其包括以下步骤:(a)使内酯与亚胺反应,得到手性二醇 公式IV; (b)氧化二醇以获得式V的醛; (c)将醛与烯醇缩合,然后脱水得到式VI化合物; (d)使式Ⅵ化合物氢化得到式Ⅶ的酮; 和(e)手性催化还原酮,其中步骤(b) - (d)显示在以下反应方案中:

    Synthesis of intermediates useful in preparing bromo-substituted
tricyclic compounds
    7.
    发明授权
    Synthesis of intermediates useful in preparing bromo-substituted tricyclic compounds 失效
    可用于制备溴代三环化合物的中间体的合成

    公开(公告)号:US5760232A

    公开(公告)日:1998-06-02

    申请号:US882753

    申请日:1997-06-16

    IPC分类号: C07D401/04 C07D221/16

    CPC分类号: C07D401/04

    摘要: The invention relates to a process for preparing a compound of the formula ##STR1## comprising: (a) reacting 2,5-dibromo-3-methylpyridine with an amine of the formula NHR.sup.5 R.sup.6 to obtain an amide; (b) reacting the amide with a compound of formula 3 ##STR2## in the presence of a strong base to obtain a compound of formula 4 ##STR3## (c) converting a compound of formula 4 to the corresponding cyano compound or aldehyde; (d) reacting the cyano compound or aldehyde with a piperidine derivative to obtain an aldehyde or alcohol of formula 7a or 7b, respectively: ##STR4## (e) cyclizing a compound of formula 7a or 7b; wherein R.sup.1 -R.sup.7 are as defined in the specification.

    摘要翻译: 本发明涉及制备式I化合物的方法,其包括:(a)使2,5-二溴-3-甲基吡啶与式NHR 5 R 6的胺反应,得到酰胺; (b)在强碱存在下使酰胺与式3化合物反应,得到式4化合物(c)将式4的化合物转化成相应的氰基化合物或醛 ; (d)使氰基化合物或醛与哌啶衍生物反应,分别得到式7a或7b的醛或醇:(e)使式7a或7b的化合物环化; 其中R1-R7如说明书中所定义。

    Process for preparing florfenicol, its analogs and oxazoline
intermediates thereto
    8.
    发明授权
    Process for preparing florfenicol, its analogs and oxazoline intermediates thereto 失效
    制备氟苯尼考,其类似物和恶唑啉中间体的方法

    公开(公告)号:US5382673A

    公开(公告)日:1995-01-17

    申请号:US39450

    申请日:1993-04-22

    CPC分类号: C07D263/10 C07C317/32

    摘要: A process for preparing a compound of formula (IV): ##STR1## comprising a) contacting an oxazoline compound of formula (I): ##STR2## wherein Z is as defined hereinbefore, with a reagent capable of causing an equilibrium between oxazoline compound (I) and an oxazoline compound of formula (II) described herein, and the reagent drives the equilibrium toward oxazoline compound (II) by preferential precipitation of oxazoline compound (II);b) contacting compound (II) with a fluorinating agent to give a fluorinated oxazoline compound of formula (III) described herein; andc) hydrolyzing the compound of formula (III) to formula (IV). In an alternative embodiment, the process is directed toward a process for preparing oxazoline (II) in a single step.

    摘要翻译: PCT No.PCT / US91 / 07608 Sec。 371日期:1993年4月22日 (IV)的制备方法:包含a)使式(I)的恶唑啉化合物与式(Ⅳ)的化合物接触:(ⅰ) (I)其中Z如上所定义,与试剂能够引起恶唑啉化合物(I)和本文所述的式(II)的恶唑啉化合物之间的平衡,并且试剂将平衡转化为恶唑啉化合物(II) 通过恶唑啉化合物(II)的优先沉淀; b)使化合物(II)与氟化剂接触,得到本文所述的式(III)的氟化恶唑啉化合物; 和c)将式(III)化合物水解成式(IV)。 在替代实施方案中,该方法涉及在单步骤中制备恶唑啉(II)的方法。