B Y TTRNG I HC DC H NI V VN BCH NGHIN CU CC PHN NGNH HNG TNG HP TAMSULOSIN T L-TYROSIN KHA LUN TT NGHIP DC S H NI - 2014 B Y TTRNG I HC DC H NI V VN BCH NGHIN CU CC PHN NGNH HNG TNG HP TAMSULOSIN T L-TYROSIN KHA LUN TT NGHIP DC S

H NI - 2014 Ngi hng dn:ThS. Nguyn Vn Giang Ni thc hin:B mn cng nghip dc LI CM N Saumtthigianlmvickhntrngcsgiptntnhca ccthycgio,gianhcngbnb,tihonthnhKhalunTt nghip Nghin cu cc phn ng nh hng tng hp tamsulosin t L-tyrosin. Vi ttc s knhtrng, trctin ti xin byt lng bit n su sc nThygioThS.NguynVnGianghngdn,chbotntnhv to mi iu kin gip ti nghin cu thc hin kha lun ny. TicngxingilicmnchnthnhtiPGS.TS.Nguynnh Luyn - trng B mn Cng nghip Dc, TS. Nguyn Vn Hi, Ths. Phm Th Hin v CN. Phan Tin Thnh ca T mn Tng hp Ha dc - B mn Cng nghipDc hngdn, gip v tomi iu kin tt nht cho ti trong sut thi gian thc hin kha lun va qua. Ticngxincgilicmnnttcthy,cthucBmn CngnghipDc,cngnhccthy,ctrongTrngihcDcH Ni to iu kin thun li cho ti hon thnh kha lun tt nghip ny v dy bo ti tn tnh trong sut nm nm hc. Cui cng, ti xin gi li bit n su sc n gia nh ti, c bit l b m ti v li cm n chn thnh n bn b ti, l ngun ng lc khng th thiu,lunbntigiptisutthigianihcvtrongsutqutrnh thc hin ti Kha lun tt nghip. H Ni, ngy 15 thng 5 nm 2014 Sinh vin V Vn Bch MC LC DANH MC CC CH VIT TT DANH MC CC BNG DANH MC CC S T VN ............................................................................................... 1 Chng 1: TNG QUAN ............................................................................ 2 1.1.Tng quan v tamsulosin ................................................................. 2 1.1.1.Cu trc ha hc .......................................................................... 2 1.1.2.Tnhcht l, ha ca tamsulosin hydroclorid .............................. 2 1.1.3.nh tnh, nh lng tamsulosin hydroclorid .............................. 2 1.1.4.Bit dc ..................................................................................... 3 1.1.5.Dc ng hc ............................................................................. 3 1.1.6.Tc dng, cng dng, liu dng ................................................... 3 1.1.7.Tc dng ph v thn trng .......................................................... 4 1.1.8.Tng tc thuc ........................................................................... 5 1.2.Phng php tng hp ha hc tamsulosin .................................... 5 1.2.1.Tng hp tamsulosin bng phng php tng hp v tch hn hp racemic ..................................................................................................... 5 1.2.2.Tng hp tamsulosin bng phng php tng hp bt i ........... 6 1.2.3.Tng hp tamsulosin bo ton cu hnh t nguyn liu L-tyrosin8 1.2.4.Mt s phng php khc .......................................................... 12 Chng 2: I TNG PHNG PHP NGHIN CU ................... 15 2.1. Nguyn vt liu, thit b v dng c nghin cu ............................. 15 2.1.1. Nguyn liu v ha cht nghin cu ............................................. 15 2.1.2. Cc thit b, my mc v dng c nghin cu............................... 16 2.2. Ni dung nghin cu ........................................................................ 18 2.3. Phng php thc nghim ............................................................... 19 2.3.1. Tin hnh cc phn ng ha hc tng hp cc cht trung gian trn con ng tng hp tamsulosin t nguyn liu L-tyrosin ................ 19 2.3.2. Xc nh tinh khit cc sn phm ca phn ng ....................... 20 2.3.3. Cc phng php vt l, ho l chit tch v tinh ch cc sn phm to thnh ....................................................................................... 20 2.3.4. Phng php khng nh cu trc ................................................. 20 Chng 3: THC NGHIM, KT QU V BN LUN...................... 21 3.1. Kt qu thc nghim ........................................................................ 21 3.1.1. Tng hp N-acetyl-L-tyrosin ........................................................ 21 3.1.2. Tng hp O-methyl-N-acetyl-L-tyrosin ethyl ester ....................... 22 3.1.3. Kh ha to thnh (S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamid ......................................................................................... 25 3.1.4. Tng hp (S)-2-acetamido-3-(4-methoxyphenyl)propyl-4-methylbenzensulfonat............................................................................. 28 3.1.4.Tng hp (S)-N-[1-cloro-3-(4-methoxyphenyl)propan-2-yl]acetamid ............................................................................................ 29 3.1.5.Tng hp hp cht trung gian 13 (ether)benzoxytosylat ............. 30 3.2.Xc nh cu trc cc cht tng hp c bng phng php ph31 3.2.1.Kt qu phn tch ph IR ........................................................... 31 3.2.2.Kt qu phn tch ph MS .......................................................... 32 3.2.3.Kt qu phn tch ph 1H-NMR ................................................. 33 3.3. Bn lun ............................................................................................ 34 3.3.1. Bn lun v cc phn ng tng hp ha hc ................................. 34 3.2.2. Bn lun v kt qu phn tch ph ................................................ 37 KT LUN V KIN NGH .................................................................... 39 TI LIU THAM KHO PH LC DANH MC CC CH VIT TT AcNhm Acetyl ADRPhn ng c hi ca thuc (Adverse Drug Reactions) BPHU x tuyn tin lit (Benign prostatic hyperplasia). CbzNhm carboxybenzoyl DMSODimethyl sulfoxid EtNhm ethyl 1H-NMRPhcnghngthtnhnproton(Hydrogen-1-Nuclear magnetic resonance spectroscopy) HPLCScklnghiunngcao(High-performanceliquid chromatography) IRPh hng ngoi (Infrared spectroscopy) KLKhi lng MeNhm methyl MSPh khi lng phn t (Mass spectroscopy) RfH s lu gi (Retardation factor) SKLMSc k lp mng (Thin layer chromatography) TEATriethylamin THFTetrahydrofuran TsNhm tosyl DANH MC CC BNG Bng 2.1. Nguyn liu v ha cht nghin cu..15 Bng 2.2. Cc thit b, my mc nghin cu..16 Bng 2.3. Cc dng c nghin cu.17 Bng 3.1. T l tc nhn nh hng ti hiu sut phn ng methyl ha23 Bng 3.2. Kho st cc loi xc tc base cho phn ng methyl ha...24 Bng 3.3. nh hng ca dung mi ti phn ng kh...26 Bng 3.4. nh hng ca t l NaBH4:ester 4 ti phn ng kh...27 Bng 3.5. Kt qu phn tch ph IR31 Bng 3.6. Kt qu phn tch ph MS..32 Bng 3.7. Kt qu phn tch ph 1H-NMR.33 DANH MC CC S S 1.1. Tng hp tamsulosin t 4-methoxyphenylaceton........................5 S 1.2. Phn ng gia () tamsulosin v (-)-menthyl cloroformat..............6 S 1.3. Cc phn ng tng hp tamsulosin theo Hajicek.7 S 1.4. Tng hp (R)-tamsulosin theo R. H. Jih..8 S 1.5. Tng hp cht trung gian 2-[(2-ethoxyphenoxy)]ethyltosylnat theo R. H. Jih.....9 S1.6.Phngphptnghp(S)-4-methoxyamphetamincaH. Kohno..10 S1.7.Phngphptnghp(R)-tamsulosinhydrocloridca Dambrin...11 S 1.8: Tng hp tamsulosin theo phng php ca Prieto...12 S 1.9:Tng hp tamsulosin theo V. Chowdary.13 S2.1.Tnghp(S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamid v mt s dn cht...18 S 2.2. Tng hp cht 2-[(2-ethoxyphenoxy)]ethyltosylat181 T VN Uxtuyntinlit(Benignprostatichyperplasia-BPH)lmtcn bnh ph bin gii trung nin v cao nin, 50% s ngi n ng tui trn 50 u c cc triu chng ca BPH, 10% trong s cn phi can thip bng ni khoa hay ngoi khoa [1]. Tu vo giai on pht trin ca u x tin lit tuyn v cc triu chng m la chn cc phng php iu tr khc nhau. Cc thuc khng adrenergic trongctamsulosinangcsdngnhmtliuphpiutrBPH khichacbinchngxyra.Tamsulosincngnhccthuckhng adrenergic khc khng c hiu qu lm nh u x m ch c tc dng ci thin triu chng v phi s dng trong thi gian di [1,19,23]. Nhucusdngtamsulosiniutrlrtln.Nhnghinnay VitNam,nguynliutamsulosinsnxutthuciutrBPHuc ngungcnhpkhuvcngchacccnghincunotinxatrong nghincuccphnngtnghptamsulosin.Dovy,gpphnnghin cuhonthinquytrnhtnghptamsulosin,chngtitinhnhti NghincuccphnngnhhngtnghptamsulosintL-tyrosin. Vi mc tiu nh sau: 1.Nghin cu cc phn ng tng hp mt s cht trung gian trong quy trnh tng hp tamsulosin t L-tyrosin. 2.Khostmtsyutnhhngnhiusutccphnng quan trng trong quy trnh tng hp. 2 Chng 1: TNG QUAN 1.1.Tng quan v tamsulosin Tamsulosin l thuc i khng adrenergic s dng trong iu tr BPH. TamsulosinchaingphniquangtrongngphnRmictc dng. Cc ch phm hin hnh u s dng dng mui hydroclorid [23]. 1.1.1. Cu trc ha hc Cng thc cu to Tnkhoahc:(R)-5-(2-{[2-(2-ethoxyphenoxy)ethyl]amino}propyl)-2-methoxybenzen-1-sulfonamid. Cng thc phn t: C20H28N2O5S. Phn t khi: 408,51. Thnh phn khi lng cc nguyn t: C 58,80%, H 6,91%, N 6,86%, O 19,58%, S 7,85% [22]. 1.1.2. Tnhcht l, ha ca tamsulosin hydroclorid Cht rn mu trng hoc trng nht. Nhit nng chy: 228-230oC. DngmuiHCltantngitttrongnc,dngtdottantrong nc: Nng bo ha 6,55x10-3 g/l Nng sut quay cc ring: []D24= -4,0 (C = 0,35 trong methanol). pKa=9,93 trong acid mnh v 9,28 trong base mnh [9,22]. 1.1.3. nh tnh, nh lng tamsulosin hydroclorid nh tnh: oo ph hp th hng ngoi so snh vi chun. 3 oo nng sut quay cc ring. oPhn ng ca ion Cl-. nhlng:Chunothtrongmitrngkhanyucuhm lng pht t t 98,5% ti 101%, tnh theo ch phm lm khan [9,22]. 1.1.4. Bit dc Alfatam (Zydus Biogen), Bezip (Emcure Pharmaceuticals Ltd), Flomax (Yamanouchi),Harnal(Yamanouchi),Omnic(Yamanouchi),Uritin (OverseasHealthCarePvt.Ltd),Tamsin(ArdorDrugsPvt.Ltd),Urimax (Cipla Limited), Pradif (Boehringer, Ing.) [22]. 1.1.5. Dc ng hc Tamsulosin c hp thu gn nh hon ton qua ng tiu ha. Mc v tc hp thu gim bi thc n. Xut hin trong huyt tng ngay sau khi ung, t nng nh trong mu sau khong 1 gi. Tamsulosin l lin kt vi protein huyt tng khong 99%. ChuynhatiganchyubicytochromP450,enzymCYP2D6v CYP3A4. Bi tit ch yu trong nc tiu dng chuyn ha v mt phn nh dng cha chuyn ha. Thigianbnthit4n5,5gi.Nngtronghuyttngca tamsulosin tng nhng bnh nhn suy thn. Tuy nhin, nng trong huyt tngca dng khnglinkt vihuyttng -dngthuc chottnh li tngtngibnhthng,c kinchorngtngnngtronghuyt tngtngldosgiatngproteinhuyttngbnhnhnsuythn [14,23]. 1.1.6. Tc dng, cng dng, liu dng 4 Tamsulosinthucnhmthucchnthth1-adrenergic,tcdng chn lc trn th th 1A-adrenergic (chim khong 70% th th 1-adrenergic ti tuyn tin lit). Sdngtrongiutruxtuyntinlitgimtriuchngtc nghnngtiu.Sdngdidngvingiiphngbini,viliu400 microgram mt ngy mt ln. Nu cn thit, c th tng liu sau 2 n 4 tun iu tr ln ti a 800 microgram mi ngy mt ln. S dng iu tr thnh cng cc ri lon sinh dc-tit niu do thuc chng trm cm nh reboxetin gy ra. Tamsulosin gim triu chng vim tuyn tin lit mn tnh nam gii. Liu s dng 400 microgram/ngy. c nghin cu trong iu tr si thn, n c th lm gim co tht c trn niu qun, gim tc nghn v ci thin lng nc tiu, do lm tng t l v gim thi gian loi b si thn, gim au vi liu 400 microgram/ngy s dng trong 4 tun [23]. 1.1.7. Tc dng ph v thn trng Tamsulosin c cc tc dung ph chung ca nhm thuc c ch 1nh: C th gy ra nhng bt thng trong xut tinh. Tt huyt p t th ng nng v ngt liu u. Cc tc dng ph ph bin hn bao gm chng mt, bun ng, au u, thiu nng lng, bun nn v nh trng ngc. Thn trng: Bnhnhnsuyganhocsuythnvngicaotuidocnguyc cao b tt huyt p t th ng. Khng nn li xe hay vn hnh my mc do c th gy bun ng hoc chng mt. 5 Tamsulosin tcdngchnlclnreceptor1trong tuyntin lit,tc dng gin mch ca n t c biu hin nn cc tc dng ph ca n t ph bin hn cc thuc c ch 1 khc [19,23]. 1.1.8. Tng tc thuc S dng vi thuc li tiu, ru, thuc h huyt p, thuc khc c tc dng h huyt p c th tng nguy c tt huyt p. Nguy c h huyt p liu u c th c tng mnh nhng bnh nhn s dng thuc chn beta hoc thuc chn knh calci [23]. 1.2.Phng php tng hp ha hc tamsulosin 1.2.1. Tnghptamsulosinbngphngphptnghpvtchhnhp racemic K. Imai v cng s, tng hp tamsulosin di dng hn hp racemic t nguyn liu u l 4-methoxyphenylaceton [16]. S 1.1. Tng hp tamsulosin t 4-methoxyphenylaceton ithpcht4-methoxyphenylaceton1.1,thchinphnng clorosulfonylhabngtcnhnClSO3Hsauamidhabngdungdch NH3 thu c hp cht 1.2. Sau t 1.2 thc hin phn ng imin ha vi 2-ethoxyphenoxyethylamin(1.3)rikhhaimintothnhvitcnhnkh H2, xc tc Pt thu c tamsulosin di dng hn hp racemic [16]. 6 Sau , C. B. Fernandez v cng s xut quy trnh ring cc ng phn i quang t hn hp racemic, da trn phn ng ca tamsulosin vi (-)-menthyl chloroformat. S 1.2. Phn ng gia () tamsulosin v (-)-menthyl chloroformat Hai dn cht 1.4 v 1.5 c tch ring bng HPLC sau c thy phn tr v dng (R)-tamsulosin v (S)-tamsulosin [13]. Nhn xt:Phng php ny bc l nhiu hn ch nh phi s dng sc k ct tch c sn phm, tamsulosin thu c di dng racemic sau phi tch c ng phnR t hnhpny,phn ng khsdng xctcd th t tin 1.2.2. Tng hp tamsulosin bng phng php tng hp bt i J. Hajicek v cng s tin hnh tng hp (R)-tamsulosin bng quy trnh c m t sau y: 7 S 1.3. Cc phn ng tng hp tamsulosin theo Hajicek Clorosulfohasauamidha1-(4-methoxyphenyl)propan-2-onthu c 2-methoxy-5-(2-oxopropyl)benzensulfonamid 1.2, hiu sut t 30%. Thchinphnngiminhagiaxeton1.2vihpcht(S)-1-phenylethanamin ri kh ha imin to thnh trong methanol xc tc PtO2, tc nhnkh lH2.Sau ,acidhasnphmthu c hp cht2.2, hiu sut phn ng t 53%. Hydro ha hp cht 2.2 vi H2/MeOH xc tc Pd/C sau chuyn sn phmvdngbasebngK2CO3thuc(R)-5-(2-aminopropyl)-2-methoxy benzensulfonamid 9, hiu sut ca qu trnh t 78%. Tnghp(R)-tamsulosinbngphnnggiahpcht9v1-(2-bromoethoxy)-2-ethoxybenzen, hiu sut phn ng t 34% [15]. 8 Nhnxt:Phngphpnytnghpc(R)-tamsulosint(S)-1-phenylethanaminv1-(4-methoxyphenyl)propan-2-onvihiusutchung thp(4,2%),quytrnhphnngphctp.Hnnaphnngiminhari kh ha to thnh mt lng nh ng phn (S)-tamsulosin. 1.2.3. Tng hp tamsulosin bo ton cu hnh t nguyn liu L-tyrosin + Phng php ca R. H. Jih R.H. Jih xut phng php tng hp tamsulosin vi cc bc sau: S 1.4. Tng hp (R)-tamsulosin theo R. H. Jih 9 T L-tyrosin 1 thc hin phn ng acyl ha bng tc nhn Ac2O trong dungdchNaOH2N,esterhabngethanolvPCl3thucdncht amidoester 3 vi 2 nhm chc c bo v. Methyl ha 3 s dng tc nhn (CH3)2SO4vtriethylaminthu cdn cht(ether)amidoester4,kh ha4 bng LiAlH4 trong dung mi khan thu c dn cht (hydroxyl)ether amid 5, tosylhasaukhhabngLitrongacidoxalic,cmtLiBrnhm hydroxylscloib,thuc4-methoxyampheacetamid7[17].T7 triquaccphnng gnnhmsulfonamidvovngbenzen,thyphn nhmbovcanhmaminorichotcdngvidncht(ether) benzoxytosylat13sdngNaHCO3trongdungmiethanolthuc(R)-tamsulosin. Hp cht trung gian 13 2-[(2-ethoxyphenoxy)]ethyltosylnat c tng hp nh sau: S 1.5. Tng hp cht trung gian 2-[(2-ethoxyphenoxy)]ethyltosylnat theo R. H. Jih Tetherpyrocathechol11chotcdngvi2-cloroethanoltrongmi trngkimthucdncht12.TosylhanhmOHcahpcht12s dngtcnhntosylcloridxctctriethylamin,dungmidicloromethanthu c hp cht 13 [17]. Thyphnhpcht7bngHCl5%sthuc4-methoxyamphetamin(hpcht7)lchttrunggian quan trng trong nhiu quy trnh khc. Nhn xt: 10 Phng php ny n gin, d thc hin, cc phn ng u c hiu sut tng i cao nhng tri qua nhiu giai on, cn c nhiu hn ch cn khc phcnhsdngnhiutcnhnchi,dungmihucvmtvitc nhn kh kim. Hpcht7cngcH.Kohnovcngstnghpviquytrnh phn ng sau: S 1.6. Phng php tng hp (S)-4-methoxyamphetamin ca H. Kohno Phng php ny s dng nhm bo v amin l carboxybenzoyl (Cbz). itL-tyrosinqualnltccphnng:EstehanhmCOOHbng ethanol v SOCl2, bo v nhm NH2 bng nhm Cbz, methyl ha nhm OH phenolbngtcnhnmethyliodidvK2CO3,khhanhmestebng tetrahydroboratnatritrongethanol,tosylhanhmOHtothnhtphn ng kh, kh ha nhm hot ng tosyl s dng km trong THF xc tc natri 11 iodid, loi bnhmbo v Cbzs dng hydro khxctc Pd/C sau acid ha thu c4-methoxyamphetamin dng mui chlorid [18]. Nhn xt: Cc phn ng tin hnh tng i d dng nhng giai on loi nhm bo v khng thun tin. + Phng php ca V. Dambrin Dambrin v cng s tng hp tamsulosin cng t L-tyrosin theo s sau: S 1.7. Phng php tng hp (R)-tamsulosin hydroclorid ca Dambrin itL-tyrosinviccbcutngtR.H.Jihchotikhitng hpccht5(S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-12 yl]acetamid. i t 5, tin hnh phn ng th nhm OH bng nhm Cl, ri thaythnhmClbngnhmSCH3thuchpcht15(S)-N-[1-(4-methoxyphenyl)-3-(methylthio)propan-2-yl]acetamid.Clorosulfonamidho riloibnhmbovacetylcanhmNH2thuchp cht 16.Thc hin phn ng imin ha gia 2-(2-ethoxyphenoxy)acetaldehyd v hp cht 16 ri kh ha imin to thnh vi NaBH3CN/MeOH thu c hp cht 17. Loi nhm SCH3 17 bng phn ng kh vi H2/Ni Raney ri acid ha bng HCl long s thu c (R)-tamsulosin hydroclorid [11]. Nhn xt: Hn ch ca phng php ny l hiu sut c bo co khngphilcaongthimtsphnngihixctckhkimnn kh tin hnh. 1.2.4. Mt s phng php khc + Phng php ca J. V. Prieto Phng php ny c s dng enzym Novozym xc tc cho phn ng gia4-methoxyamphetaminvacidbromoacetic,quytrnhphnngc m t theo s di y: S 1.8: Tng hp tamsulosin theo phng php ca Prieto 13 KhcviR.H.Jih,Prietovcngsit4-methoxyamphetamin7, quaccphnngviacidbromoacetic,ccphnngclorosulfonamidha, ri cho tc dng vi pyrocatechol ethyl ether thu c dn cht amid 4.3. Kh ha nhm amid ca 4.3 bng NaBH4 c mt BF3 ri acid ha s thu c sn phm tamsulosin hydroclorid [21]. Nhn xt: Phng php trn cho hiu sut cao nhng khng ra quy trnh tng hpcht4-methoxyamphetaminvsdngcctcnhn,xctckhkim trong iu kin tin hnh ti. + Phng php tng hp tamsulosin ca V. Chowdary PhngphpcaV.Chowdaryithpcht7quaccphnng trong s sau y: S 1.9:Tng hp tamsuloson theo V. Chowdary 14 Phng php cng i t hp cht 7 qua phn ng vi benzaldehyd, phn ngvi1-ethoxy-2-(2-iodoethoxy)benzen,rithyphn,acidhathu c tamsulosin hydroclorid [10]. Trongccphngphpcptrn,ccphngphptnghp tamsulosin t nguynliuL-tyrosinc nhiu u im nhl nguynliu s dngdtm,cthsnxutvilngln,snphmphnngkhngphi tchhnhpracemic,iukinphnngddng,chohiusutcao,qu trnh tch sn phm khng qu phc tp. Trong cc phng php i t nguyn liu L-tyrosin nhn thy quy trnh caR.H.Jihnginmchohiusutcao,ckhnngthchinc trongiukinthctcaVitNam.Chngtiquytnhlachncon ng ny tin hnh nghin cu tng hp tamsulosin. Trong phm vi ti ny, chng ti tin hnh nghin cc phn ng tnghpcccht2,3,4,5,6,12,13,14theoquytrnhcaR.H.Jihng thi ci tin trong mt s phn ng thu c hiu sut cao nht. 15 Chng 2: I TNG PHNG PHP NGHIN CU 2.1. Nguyn vt liu, thit b v dng c nghin cu ti s dngmt s nguyn liu, ha cht, dungmi v thit b ca phng th nghim Tng hp Ha dc, B mn Cng nghip Dc. 2.1.1. Nguyn liu v ha cht nghin cu Bng 2.1. Nguyn liu v ha cht nghin cu STTTn nguyn liu v ha chtNgun gc 1.L-tyrosinVit Nam 2.Acid aceticTrung Quc 3.Acid hydrochloricTrung Quc 4.Acid sulfuricTrung Quc 5.AcetonTrung Quc 6.Anhydrid aceticTrung Quc 7.2-CloroethanolMerck 8.Dimethyl sulfatMerck 9.DicloromethanTrung Quc 10.EthanolTrung Quc 11.Ethyl acetatTrung Quc 12.Giy ch th vn nngTrung Quc 13.Kali carbonatTrung Quc 14.Natri cacbonatTrung Quc 15.Natri hydroxydTrung Quc 16.NinhydrinTrung Quc 17.Natri tetrahydridoboratMerck 18.PyridinTrung Quc 19.Triethyl aminMerck 16 20.p-toluensunfonyl cloridMerck 21.ToluenVit Nam 22.Thionyl cloridB 2.1.2. Cc thit b, my mc v dng c nghin cu Bng 2.2. Cc thit b, my mc nghin cu STTTn thit b, my mcNgun gc 1.Cn k thut Sartorius BP2001Sc 2.Cn phn tch Mettler Toledo AB204SThy S 3.My ct quay Buchi Rotavarpor R-210Thy S 4.My o nhit nng chy EZ- MeltM 5.My o pHc 6. My o ph cng hng t ht nhn proton 1H-NMR Bruker AV- 500MHz M 7.My o ph hng ngoi Perkin ElmerM 8.My o ph khi lng LC-MSD-Trap-SLc 9. MyophkhilngphngiicaoFT-ICR-MS-Varian 910MS c 10.My khuy t gia nhit IKAc 11.T sy Memmertc 17 Bng 2.3. Cc dng c nghin cu STTTn dng cNgun gc 1.Bn mng Silicagel GF254 70- 230 meshc 2.Bnh cu 2 c 250ml v 2lc 3.Bnh cu y trn loi 50ml, 250ml, 500mlc 4.Bnh phun sc kTrung Quc 5.Cc c m 100ml, 250ml, 500mlTrung Quc 6.a thy tinh, pipet pasterTrung Quc 7.Nhit k thy ngnTrung Quc 8.Phu lc BuchnerTrung Quc 9.Pipet chnh xc 1ml, 5ml, 10mlTrung Quc 18 2.2. Ni dung nghin cu Tnghphohc:Chngtitinhnhccphnnghahc tng hp c cc cht trung gian trong quy trnh tng hp tamsulosin t L-tyrosin theo R. H. Jih gm c cc hp cht 2, 3, 4, 5, 12, 13, 14 v hp cht 15. Cc cht c tng hp theo s sau: S 2.1. Tng hp (S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamid v mt s dn cht Tnghphpchttrunggian132-[(2-ethoxyphenoxy)]ethyltosylat theo s : S 2.2. Tng hp cht 2-[(2-ethoxyphenoxy)]ethyltosylat 19 Cc phn ng quan trng to thnh cc hp cht 4 v 5 c kho st mt s yu t nh hng. Cc sn phm tng hp c kim tra tinh khit v khng nh cu trc phn t. 2.3. Phng php thc nghim 2.3.1.Tinhnhccphnng hahctnghpccchttrunggiantrn con ng tng hp tamsulosin t nguyn liu L-tyrosin Phng php tng hp c lachndatrn c s: nguynliu sn c, iu kin phn ng ph hp vi cc iu kin th nghim hin c ti Vit Namvphngthnghim,nhmnhhngchovichonthinquytrnh tng hp tamsulosin t L-tyrosin. NguynliuL-tyrosin:L-tyrosincchittchratdchthuphn cc ngun keratin khc nhau (sng, lng, tc, mng) trong mi trng acid. L-tyrosin l ph phm ca quy trnh chit tch L-cystin lm nguyn liu bn tnghpN-acetyl-L-cysteintrongticpNhnccnghimthu thnhcngthchinbiPGS.TSNguynnhLuyn.Ngunnguynliu nysnc,ckhnngpngchonhucusnxutquymcng nghip [4,6,7]. Cc phn ng c s dng l acetyl ha, ester ha, kh ha, tosyl ha, phn ng th nhm ancol bng halogen v 2 phn ng ankyl ha. Phn ng c theo di bng phng php sc k lp mng vi: -Pha tnh: Silicagel GF254 -Pha ng: dicloromethan: methanol = 9: 1, dicloromethan:methanol = 60:1. -Pht hin bng n t ngoi bc sng 254nm, thuc th hinmu: dung dch ninhydrin/aceton, nng 1%. 20 2.3.2. Xc nh tinh khit cc sn phm ca phn ng -Phng php sc k lp mng ging nh m t trn. -Phngphponhitnngchytrnmyonhitnngchy EZ- Melt. 2.3.3. Cc phng php vt l, ho l chit tch v tinh ch cc sn phm to thnh -Cc phng php chit tch: S dng dung mi hu c hoc dung mi thn nc. -Cc phng php kt tinh: Ct loi dung mi, thay i dung mi, thay i nhit -Cc phng php lc: Lc ht chn khng, lc di p sut thng 2.3.4. Phng php khng nh cu trc Cc cht tng hp c xc nh cu trc bng cc loi ph sau: ph hng ngoi(IR),phkhilng(MS),phcnghngthtnhnproton(1H-NMR). -Ph hng ngoi (IR): ph hng ngoi c ghi trn my Perkin Elmer vi k thut vin nn KBr trong vng 4000-400cm-1. Ccmu rn c phn tn trong KBr sy kh vi t l 1:200 ri p di dng film mng di p lc cao c ht chn khng loi b hi m . -Ph khi lng(MS): ph khi lngcc cht cghi bng myo phkhilngLC-MSD-Trap-SLvmyophkhilngphngiicao FT-ICR-MS-Varian910MStiVinhohc-VinHnlmKhoahcv Cng ngh Vit Nam. -Ph cng hng t ht nhn (1H-NMR) c ghi trn my Bruker AV-500 ti Vin ha hc - Vin Hn lm Khoa hc v Cng ngh Vit Nam. 21 Chng 3: THC NGHIM, KT QU V BN LUN 3.1. Kt qu thc nghim 3.1.1. Tng hp N-acetyl-L-tyrosin S phn ng: +Cchtinhnh:TinhnhtheophngphpcWillianThomas Brady m t [2,11,17]. Chovobnhcuhaic2l:27,00g(0,15mol)L-tyrosin,48,0mlH2O, 75,0mlNaOH2M,khuychotanhonton.Lmlnh bnhcubngnc xung 5oC. Nh t t vo hn hp 8 ln, mi ln 45,0 ml NaOH 2M v 4,5 ml anhydrid acetic, duy tr nhit di 5oC bng nc v m bo NaOH 2M lun cho trc trong sut qu trnh nh. Tip tc khuy nhit phng thm 30 pht loi anhydrid cn d. Sau iu chnh dung dch phn ng ti pH=2 bng 201,0 ml H2SO4 6N. t lnh qua m L-tyrosin d kt ta. Lc b phn ta, ct quay n kit phn dch lc thu c cht rnmu trng. Thm 250,0 ml ethanol 96o ha tan N-acetyl-L-tyrosin, lc b phn mui khng tan, ct chn khng n kit dch lc, ct thm 40 pht loi ht acidaceticthucchtbnrnmuvngnht.Thm40,0mlH2O,sn phmnhanhchngkttinh,lc,rabngHCl1N2ln,rirabngnc, sy kh thu c cht kt tinh mu trng. Kt qu: -Khi lng sn phm 26,82 g, hiu sut th 80,62%. -Kttinhlitrongmethanolthuctinhthkhngmuhnhkim, nhit nng chy 149-150oC (152-153oC theo ti liu [17]). 22 -Scklpmngcho1vtRf=0,54(dicloromethan:methanol=9:1), phun ninhydrin khng hin mu. 3.1.2. Tng hp O-methyl-N-acetyl-L-tyrosin ethyl ester TN-acetyl-L-tyrosintnghpcO-methyl-N-acetyl-L-tyrosin ethyl ester phi tri qua 2 phn ng ester ha v O-methyl ha. -Tng hp N-acetyl-L-tyrosin ethyl ester bng phn ng ester ha Chngtitinhnhphnngesterhatrongiukintiuc kho st trong Lun vn Thc s ca Th.S Nguyn Vn Giang [2]. Thmvobnhcu2c250ml18,4mlethanol,lmlnhbnngoibnh cu bng nc xung 5oC. Nh cn thn t t 9,5 ml SOCl2 vo bnh phn ng. un hi lu hn hp trong 1 gi loi ton b kh HCl sinh ra. Thm vokhiphnngdungdch22,30g(0,1mol)N-acetyl-L-tyrosinhatan trong 55,0 ml ethanol. Tip tc un hi lu trong 3 gi th phn ng kt thc. Ct quay n kit khi phn ng thu c cht bn rn mu vng nht. Sc k cho mt vt Rf=0,57 (h diclomethan: methanol= 9: 1). Nhn thy sn phm th 3 khng cha cc tp c th nh hng ti phn ng sau v cha rt t nc chng ti quyt nh s dng n tin hnh phn ng tip theo. -TnghpO-methyl-N-acetyl-L-tyrosinethylesterbngphnngO-methyl ha vi tc nhn dimethyl sulfat Phn ng s dng sn phm th t phn ng ester ha: 23 Thm vo bnh cu 2 c 130,0 ml aceton, ton b lng cht 3 th thu ctrn,khuymnhhatanhtcht3.Thm21,00g(0,15mol) K2CO3 khancnghinnh,khuytrong30pht.Nhtt10,9ml (0,12mol)dimethylsulfatvohnhpphnng.Khuytiptrong24gi. Lc phn rn, ct quay dch lc n kit thu c cht rn mu trng ng. tm c iu kin ti u cho phn ng tng hp hp cht 4 chng ti tin hnh kho st mt s yu t nh hng ti phn ng methyl ha: t l tc nhn dimethyl sulfat: ester 3; base s dng cho phn ng. Ester 3 s dng trong cc kho st c kt tinh li trong ethanol 30o t sn phm th.Kho st t l tc nhn dimethyl sulfat : ester 3 vi cc iu kin sau: Nhit phn ng l: 205oC. T l mol dimethyl sulfat : ester 3 kho st l 1,0; 1,1; 1,2; 1,3; 1,4. Thi gian: 24h Base l K2CO3 vi khi lng 0,42 g (3mmol). Khi lng ester 3: 0,50 g (2mmol). Kt qu kho st t l tc nhn dimethyl sulfat : ester 3 thng k trong bng 3.1. Bng 3.1. T l tc nhn nh hng ti hiu sut phn ng methyl ha STT Th tch dimethyl sulfat (ml) T l mol dimethyl sulfat : ester 3 Khi lng sn phm (g) Hiu sut phn ng (%) 10,191,00,4381,5 20,211,10,4687,1 30,231,20,4789,0 40,251,30,4890,9 50,271,40,4789,0 24 Nhn xt:Hiusutphnngnhnchungtngkhitngtldimethylsulfat nhngskhcbitkhngnhiukhitngtlt1,2ln1,3v1,4.Do chng ti la chn t l dimethyl sulfat l 1,2 so vi ester 3. Kho st cc loi base s dng cho phn ng vi cc iu kin sau: Nhit phn ng l: 200C. T l mol dimethyl sulfat : ester 3=1,2. Khi lng 3: 0,50 g (2mmol). Cc loi base kho st: NaOH rn, K2CO3 khan, TEA, pyridine vi t l mol: ester 3=1,5. Kt qu kho st ny ghi li trong bng 3.2 di y. Bng 3.2. Kho st cc loi tc nhn base cho phn ng methyl ha STTXc tc s dng Thi gian (Gi) Khi lng sn phm (g) Hiu sut phn ng (%) 1NaOH rn80,2954,9 2K2CO3 khan240,4789,0 3TEA24Khng phn ng0 4Pyridin24Khng phn ng0 Nhn xt: Vi cc tc nhn base TEA v pyridin, phn ng khng din ra (c th do b ln nc). Vi NaOH rn phn ng din ra nhanh tuy nhin khng hon ton. Sc k lpmng cho kt qu ging nhau vi thi gian 8 gi v 24 gi. Nh vy phn ng gia nhm OH phenol v NaOH gii phng H2O gy thy phn tc nhn dimethyl sulfat lm gim hiu sut phn ng. Tc nhn K2CO3 khan cho hiu sut tt nht. 25 Tccktqukhost,chngtisdngtrctipsnphmtht phn ng ester ha tin hnh phn ng nhit phng, s dng K2CO3 khan, t l dimethyl sulfat: amid 2=1,2. Kt qu thu c t hai phn ng ester ha v O-methyl ha: - T 22,30 g hp cht 2, KL O-methyl-N-acetyl-L-tyrosin ethyl ester thu c l 23,10 g. Hiu sut chung ca 2 phn ng ester ha v methyl ha t 87,17%. Kt tinh li trong cn 30o thu c 4 di dng tinh th mu trng. - Sc k cho 1 vt duy nht Rf =0,70 (h diclomethan: methanol=9:1). - Nhit nngchyt 139-140oC(kttinh litrongethylacetat, 141-142oC theo ti liu [16]). 3.1.3.Khhatothnh(S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamid Tng hp (S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamid theo phn ng sau: Chng ti s dng phng php ca H. Kohno v cng s tin hnh phn ng kh hp cht 4 [18]. (Phng php ca H. Kohno tin hnh i vimt ester tng t hp cht 4). Hatan9,27g(35mmol)O-methyl-N-acetyl-L-tyrosinethylester trong 50,0 ml ethanol 96o trong bnh cu 500ml. Lm lnh bn ngoi bnh cu bngncti5oC.Thmvodungdchphnng3,30g(87mmol) NaBH4rn.Tiptckhuynhitphngthm7githphnnghon tt. Thm t t vo khi phn ng c lm lnh bng nc 5,0 ml aceton loiNaBH4 d.Nht t vo hn hp 6,5mlHClc chuyn 26 hp cht 5 sang dng t do. Ct quay n kit, thu c hn hp cht rn A, thm 5,0 ml H2O, chit bng ethylacetat 3 ln, mi ln 25,0 ml. Lm khan pha hu c bng Na2SO4 khan. Ct quay n kit pha hu c, thm 10,0 ml H2O, (S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamidkttinhdi dng tinh th khng mu. + Kt qu: KL sn phm 7,12 g, hiu sut 91,7%. Nhit nng chy t 97-99oC (kt tinh li trong ethyl acetat: n-hexan t l 1:1, 97-99oC theo ti liu [17]). SKLM cho mt vt Rf=0,37 (dicloromethan: methanol = 9: 1). Chng ti tin hnh kho st mt s yu t nh hng ti hiu sut v thigiancaqutrnhphnngkh:dungmi, tltcnhnkhNaBH4. Tin hnh vi 0,50 g (1,9 mmol) O-methyl-N-acetyl-L-tyrosin ethyl ester, ti nhit phng. + Kho st nh hng ca dung mi. Kt qu kho st vi cc dung mi THF, ethanol tuyt i, ethanol 96o, ethanol 80o (t l tc nhn kh NaBH4: ester 4=2,5) thu c trong bng 3.3.Bng 3.3. nh hng ca dung mi ti phn ng kh STTDung mi Thi gian phn ng kt thc (gi) Khi lng sn phm (g) Hiu sut phn ng (%) 1THFKhng phn ng00 2 Ethanol tuyt i 10h0,3480,81 3Ethanol 96o 7h0,3378,43 4Ethanol 80o 5h0,2968,92 27 Nhn xt: Phn ng kh vi tc nhn NaBH4 khng din ra vi dungmi khng phn cc. Vi dung mi ethanol, tng t l nc s lm gim thi gian phn ng nhngcng lmgimhiusutphn ng.Tuynhin, thayethanoltuyti bngethanol96o hiusutthayikhngngk.Docthsdng ethanol 96o thay th. + Kho st nh hng ca t l tc nhn kh NaBH4: ester 4. KhostvitlNaBH4:ester4l2;2,5;3;3,5(sdngdungmi ethanol 96o ). Kt qu ca kho st c ghi li trong bng 3.4. Bng 3.4. nh hng ca t l NaBH4: ester 4 ti phn ng kh STT Khi lng NaBH4 (g) T l mol NaBH4: ester 4 Thi gian phn ng kt thc (gi) Khi lng sn phm (g) Hiu sut phn ng (%) 10,1428,50,3276,05 20,182,570,3378,43 30,22370,3378,43 40,263,570,3378,43 Nhn xt: TlNaBH4 :ester4tngt2ln2,5lnthigianphnnggim nhngkhi tng t 2,5 ln ln 3,5 ln thi gian khng gim na do NaBH4 t ti trng thi bo ha trong ethanol 96o. Khi tng t l NaBH4 trong khong t 2 n 3,5 ln so vi ester 4 hiu sut thay i khng ng k. 28 tit kim tc nhn NaBH4 c th s dng t l 2,5 tin hnh phn ng Nh vy chng ti la chn dung mi ethanol 96o, lng tc nhn kh gp 2,5 so vi ester 4, iu kin nhit phng tin hnh phn ng. 3.1.4. Tng hp (S)-2-acetamido-3-(4-methoxyphenyl)propyl-4-methylbenzen sulfonat Cc phn ng tosyl ha 5 c cc tc gi thc hin vi xc tc chuyn pha n-Bu4NHSO4 hoc xc tc TEA. gim lng dung mi hu c phi s dng v trnh s dng cc xc tc kh kim, chng ti nghin cu phn ng tosyl ha vi xc tc pyridin v vi NaOH/Na2CO3 bo ha. a, Tosyl ha vi xc tc pyridin Phn ng nh sau: Hatan0,50 g(2,2 mmol) hpcht 5 trong 5,0mlpyridin trongbnh cu50ml.Lmlnhbnhphnngbngnc,thm0,63g(3,3mmol) tosylcloridvokhiphnng,khuyt.Duytrnhitbnngoi0oC. Sau2tingkhuytrn,tlnhquamrictchnkhngloiht pyridin, thu c cht bn rn. Thm 15,0 ml aceton ha tan cht bn rn trn, dungdch14 trong aceton vo nc thu c ta.Lctara bng HCl 1N 2 ln, ri ra bng H2O. Kt qu: -Thu c 0,21 g dn cht tosylat, hiu sut 25,20%. -Rf = 0,84 (diclomethan: methanol = 9: 1). -Nhit nng chy 78-80oC (80-81o trong ti liu [18]). Nh vy tin hnh trong pyridin phn ng xy ra vi hiu sut rt thp, khng th p dng trong cng nghip. 29 b, Tosyl ha vi NaOH/Na2CO3 Tosyl ha vi NaOH/Na2CO3 theo phn ng di y: Ha tan 0,50 g (2,2 mmol) hp cht 5 trong 15,0 ml diclomethan trong bnhcu50ml.Lmlnhbnngoibnhcubngnc.Thm0,50g (2,62 mmol) tosyl clorid vo hn hp. Nh git 2,0 ml dung dch Na2CO3 bo ha vo khi phn ng, ri sau thm 0,20 g (5 mmol) NaOH rn. Duy tr nhit bn ngoi bnh l 00C v khuy trn mnh trong sut qu trnh phn ng. Sau 1,5 gi phn ng din ra hon ton, thm 15,0 ml H2O, chit ly pha hu c ri ra bng NaOH 2N 2 ln, mi ln 15,0 ml loi tosyl clorid d, ra tip bng nc. Lm khan pha hu c ri ct quay n kit thu c cht bn rn mu vng nht. Kt qu: KL sn phm= 0,70 g. Hiu sut 84,37%. Kt tinh li trong ethyl acetat-n-hexan cho cht rn khng mu. Rf=0,84 (diclomethan:methanol=9:1).Nhitnngchy79-81oC(80-81oCtheo ti liu [18]). 3.1.4.Tng hp (S)-N-[1-cloro-3-(4-methoxyphenyl)propan-2-yl]acetamid Phn ng nh sau: Thmtt0,72mlthionylcloridvodungdchca2g(S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamidtrong10,0mltoluenti nhit phng. un hi lu hn hp trong 2h ri lm lnh v nhit phng. 30 Ctchnkhngtikit,rithm5,0mlncthuctinhthvngnhtca 14. Kt qu: -KL sn phm=1,82 g, hiu sut 84%. -Rf=0,78 (diclomethan: methanol = 9: 1). -Nhit nng chy=74-77oC (cha tm c ti liu cng b nhit nng chy). 3.1.5.Tng hp hp cht trung gian 13 (ether)benzoxytosylat Tnghpchttrunggian2-[(2-ethoxyphenoxy)]ethyltosylnattheo2 phn ng di y: Thm13,1mlcloroethanolvodungdchca5,0ml2-ethoxyphenol ha tan trong 118,7ml NaOH 1N. Hn hp sau 48 gi khuy trn to thnh 2-(2-ethoxyphenoxy)ethanol 12 kt ta dng keo. Chit khi phn ng 3 ln x 20,0mlethylacetat.Radchchitbngnc,lmkhandchchitbng Na2SO4 ri ctquaynkit thu c cht bnrnmu vng.Thm 5,0ml H2O, lnh, gi bnh cu thu c 12 dng kt ta mu vng nht. Kt qu: -KL sn phm 5,92 g, hiu sut t 84,47%. -SKLMchomtvtviRfocbng0,78trongdicloromethan: methanol = 9: 1 v bng 0,29 trong dicloromethan: methanol = 60: 1. i t 0,50 g hp cht 12 tng hp dn cht tosylat theo phng php cmttrongphntosylha(S)-N-[1-hydroxy-3-(4-methoxyphenyl)propan-2-yl]acetamidvitcnhntosylcloridvNaOH/Na2CO3 kt qu thu c: 31 Khi lng sn phm 0,59g. Hiu sut 73,5%. SKLMchomtvtviRf=0,71vihdungmikhaitrin dicloromethan: methanol = 60: 1. Nhit nng chy 81-83oC (kt tinh li trong diclomethan - n-hexan, theo ti liu [17] l 82-83oC). 3.2.Xc nh cu trc cc cht tng hp c bng phng php ph 3.2.1. Kt qu phn tch ph IR Bng 3.5. Kt qu phn tch ph IR Ph lc ChtCng thc cu to nh hp th (cm-1) Nhm chc 12 3539O-H phenol 3326N-H amid 3100-3400 O-H lin kt H 3030C-H thm 2958, 2851C-H no 1734C=O acid 1656C=O amid 1544, 1455C=C thm 1254C-O 24 3343N-H amid 3050C-H thm 2974, 2834C-H no 1742C=O ester 1652C=O amid 1520,1450C=C thm 1254C-O ester 32 35 3350O-H alcol 3337N-H amid 3100-3300 O-H lin kt H 2946, 2860C-H no 1653C=O amid 1510,1436C=C thm 1249 C-O 46 3229N-H amid 2936, 2836C-H no 1716C=O amid 1616,1518,1438 C=C thm 1328S=O 1251C-O Nhn xt: Ph hng ngoi ca cc cht c trnh by bng 1.8, kt qu cho nhng di hp th c trng ca cc nhm chc tng ng vi cc cht c phn tch [Ph lc 1,2,3,4]. 3.2.2. Kt qu phn tch ph MS Bng 3.6. Kt qu phn tch ph MS Ph lcCht phn tchMm/zMnh 54265288[M+Na]+ 65223246[M+Na]+ 76377400[M+Na]+ 33 Nhnxt:KtquphntchphMStrongbng3.6chothyph khi lng ca tng cht u cho pic phn t c s khi ph hp khi lng phn t d kin ca cht cn phn tch [Ph lc 5,6,7]. 3.2.3. Kt qu phn tch ph 1H-NMR Bng 3.7. Kt qu phn tch ph 1H-NMR (tn s 500 Mhz, cht 4: dung mi DMSO; cht 5, 6 dung mi MeOD) Ph lc Cht phn tchKt qu phn tch 8 Hp cht 4 1,11 (3H, t, -CH2-CH3) 1,79 (3H, s, CH3-CO-) 2,81 (1H, dd, H3) 2,91 (1H, dd, H3) 3,71 (3H, s, CH3-O-) 4,03 (2H, dd, -CH2-OCO-) 4,37 (1H, m, H2) 6,83 (2H, d, H3,,H5,) 7,12 (2H, d, H2,, H6,) 8,26 (1H,d, N-H) 9 Hp cht 5 1,90 (3H, s, CH3-CO) 2,66 (1H, dd, H3) 2,84 (1H, dd, H3) 3,52 (2H, m, H1) 3,76 (3H, s, CH3-O) 4,06 (1H, m, H2) 6,84 (2H, d, H2,, H6,) 7,15 (2H, d, H2,, H6,) 34 10 Hp cht 6 1,97 (3H, s, CH3-Ar) 2,41 (3H, m, CH3-CO) 2,57 (1H, dd, H3) 3,61 (1H, m, H2) 3,77 (3H, s, CH3-O) 3,91 (1H, dd, H1) 4,01 (1H, dd, H1) 6,7-7,56(8H, d, H3a, 5a, 2a, 6a, 3b,5b,2b,6b) Nhn xt: Ph 1H-NMRcacchpchtchocctnhiuprotonphhpvicc cng thc d kin [Ph lc 8,9,10]. 3.3. Bn lun 3.3.1. Bn lun v cc phn ng tng hp ha hc + Phn ng acetyl ha Phng php acetyl ha bng cch un trc tip L-tyrosin/H2O c mttrongnhiutiliu[11,17].Phngphpnynginhnnhngs dnglng tc nhn alhydridd lnhn v gp phi btli trong qu trnh thchinlrtkhctkitacidacetictoratrongphnng.iuny lm sn phm N-acetyl-L-tyrosin khng kt tinh c trong dung dch nc. NaOH ng vai tr l cht xc tc cho phn ng v to mui vi nhm COOH ca L-tyrosin. Trong qu trnh phn ng NaOH phi lun d trnh tothnhsnphmdiacylvtothnhazolactongyracemictheocch sau: 35 Tuy nhin cng khng c NaOH d qu nhiu v duy tr nhit thpmcch ltrnh thyphnlin kt amid.Qu trnhct quayphi loi b c hon ton acid acetic nu khng N-acetyl-L-tyrosin s khng kt tinh c. Giai on acid ha bng H2SO4 mc ch chuyn hp cht 4 v dng tdotdngmuiNavtomuisulfatlmkttinhL-tyrosind.Trong giaionny phiadungdchvpH thp(pH