2-acetyl-5,6,7,8-tetrahydro

Selectivity (individual impurity) and optical purity of the batch and micro-reaction technology (MRT) processes for (S)-2-acetyl tetrahydro ran synthesis... 

Furan 2-(Methylsulfinyl-acetyl)-tetrahydro- VII/2a, 598 Pentansaure 5-Acetylthio- IX, 751 Propan 2-Acetoxy-3-acetylthio- IX, 164... 

Methyl.5-[2-ozo-3-acetyl-tetrahydro° fuiylidBn.(4)]-pjTrolon.(4).oarbon a4ure-(3). thylMter 87II 407. 

In the first catalytic, enantioselective version of the Pictet-Spengler reaction, Jacobsen utilized the chiral thiourea derivative 171 as catalyst (Equation 12) [132], Such thioureas have emerged as a versatile class of chiral promoters and have proven to be of general utility in a number of enantioselective transformations [40], A particularly interesting feature of this study is the fact that in situ acetylation of the intermediary aldimine leads to an N-acyl iminium ion as the reactive species that subsequently undergoes cyclization. A priori, the more basic imine resulting from condensation of aldehyde 170 with tryptamine 169 would have been expected to be more likely than the N-acyl iminium ion to interact with catalyst 171. Nonetheless, the latter species was responsive to the H-donor catalyst, leading to N-acetylated tetrahydro-/ -carboline 172 in 81 % yield and 93 % ee [132],... 

D-fMO MO-Nonitol, 2,6-anhydro-3,S,7-trideoxy-l-C-([hydroxy-(tetrahydro-2-methoxy-5,6-dimethyl-4-methylene-2 H-pyran-2-yl) acetyl] amino)-5,5-di methyl-1, S,9-tri-0-rriethyl-, 2R-[2( j(,2[S (5-q], 5P,6P] -... 

Pterin, 6,7,7-trimethyl-7,8-dihydro-bacteriostatic activity, 3, 325 Pterin, 5,6,7-trimethyl-5,6,7,8-tetrahydro-dihydrochloride monohydrate X-ray analysis, 3, 281 Pterin-6-carbaldehyde, JV -acetyl-synthesis, 3, 312... 

H-Pyran-2,4-dione, 3-acetyl-6-methyl-food preservative, 1, 410 Pyran-2,6-dione, tetrahydro-polymers, 1, 313 Pyrandiones synthesis, 3, 793... 

Thiazole, 4-methyl-5-(2-hydroxyethyl)-in thiamine biosynthesis, 1, 97 Thiazole, 4-methyl-2-methylami nosynthesis, 6, 300 Thiazole, 4-methyl-2-phenyl-alkylation, 6, 256 mercuration, 6, 256 Thiazole, 2-(methylthio)-methylation, 6, 290 thermodynamic values, 6, 291 Thiazole, 2-methylthio-5-phenyl-synthesis, 5, 153 Thiazole, 4-methyl-5-vinyl-occurrence, 6, 327 Thiazole, 2-phenyl-acetylation, 6, 270-271 Conformation, 6, 237 synthesis, 5, 113, 6, 306 Thiazole, 4-phenyl-conformation, 6, 237 2,5-disubstituted synthesis, 6, 304 Thiazole, 5-phenyl-conformation, 6, 237 Thiazole, 2-phenyl-5-triphenylmethyl-synthesis, 6, 265 Thiazole, 2-(2-pyridyl)-metal complexes, 5, 51 6, 253 Thiazole, 4-(2-pyridyl)-metal complexes, S, 51 6, 253 Thiazole, tetrahydro-ring cleavage, 5, 80 Thiazole, 2,4,5-trimethyl-occurrence, 6, 327... 

Acetyl-7,8-d1methyl-2-oxa-4-azabicyclo[4.3,0]non-7-en-3-one 2(3H)-Benzoxazolone, 3-acetyl-3a,4,7,7a-tetrahydro-5,6-dimethyl-(9) (65948-43-8)... 

Pellotine and Anhalonidine. The A -acetyl derivative of mezcaline (I NHj— NHAc), on treatment with phosphoric oxide, yields 6 7 8-trimethoxy-l-methyl-3 4-dihydrowoquinoline (picrate, m.p. 181-2°), which, on successive catalytic hydrogenation and treatment with methyl sulphate, yields 6 7 8-trimethoxy-l 2-dimethyl-l 2 3 4-tetrahydro-isoquinoline identical with 0-methylpellotine (picrate, m.p. 167-8°), whence it appears that pellotine must be a dimethyl ether of 6 7 8-trihydroxy-1 2-dimethyl-l 2 3 4-tetrahydrowoquinoline. Pellotine and anhalonidine on complete methylation yield the same product, and as anahalonidine is a secondary base and differs from pellotine by containing —CHj less, it must be a dimethyl ether of 6 7 8-trihydroxy-l-methyl-1 2 3 4-tetrahydrowoquinoline, and pellotine should be A -methyl-anahalonidine. 

The acetylation of isotripiperideine by means of a ketone in nonpolar media affords a compound which decomposes in acidic media to piperideine and a monoacety.l derivative of the enamine form of tetrahydro-anabasine (195). This monoacetyl derivative is identical with the alkaloid amodendrine (312). A similar acylation with cinnamoylchloride affords the alkaloid orensine (196) (313), the optically active form of which is the natural alkaloid adenocarpine (314). The hydrolysis of alkaloid santiaguine gives a-truxilic acid (314). 

Proceeding from 5 -0-acetylazauridine (80), a mixture of 2 - and 3 -monophosphates (81, 82) was prepared by phosphorylation with polyphosphoric acid, and these were converted into the 2, 3 -cyclic phosphate (83). From the 2, 3 -0-isopropylidene derivative of 3-methyl-6-azauridine the 5 -phosphate was prepared by treatment with cyanoethylphosphate and the corresponding diphosphate from its morpholidate through the action of phosphoric acid. ° Furthermore, a diribonucleoside phosphate (85) with a natural 3 -5 internucleotide linkage was prepared from 6-azauridine, The starting material for the preparation of such derivatives was 5 -0-acetyl-2 -0 -tetrahydro-pyranyluridine-3 -phosphate (84) which was condensed with di-G-acetylazauridine (86) or with 2b3 -0-isopropylidene-6-azauridine (76) with the aid of dicyclohexylcarbodiimide. ... 

Acetylation of a 3,4-dihydro-j8-carboline derivative has been reported. O. Fischer described an A-acetylharmaline which was formulated as 310 since on controlled permanganate oxidation it yielded a neutral product (311), which on hydrolysis gave 7-methoxy-l-oxo-l,2,3,4-tetrahydro-j8-carboline (313) the constitution of 313... 

Acylation of l,2,3,4-tetrahydro-j8-carboline derivatives takes place preferentially at the pyr-N. Thus l,2,3,4-tetrahydro-j8-carboline yields a 2-formyl and a 2-acetyl derivative, which give 2-methyl- ... 

The relative stereostructure of 9-acetyl-7-hydroxy-l,2-dimethyl-7-meth-oxycarbonyl-4-phenyl-6-oxo-l, 4,7,8-tetrahydro-6/7-pyrido[l, 2-u]pyri-midine-3-carboxylate 122 was justified by an X-ray diffraction analysis (97JOC3109). The stereochemistry and solid state structure of racemic trans-6,9-//-l, 6-dimethyl-9 z-ethoxy-9-hydroxy-4-oxo-l,6,7,8,9,9 z-hexahydro-4//-pyrido[l,2- z]pyrimidine-3-carboxylate (123), adopting a cw-fused conformation, were determined by X-ray investigations (97H(45)2175). 

In boiling ethanol, under nitrogen and in the presence of palladized charcoal, 2-acetyl-l,4-dihydro-3-methylquinoxaline (30) undergoes dismutation to give a mixture of 2-acetyl-3-methylquinoxaline, 2-acetyl-l,2,3,4-tetrahydro-3-methylquinoxaline (33), and 2-l -hydroxy-ethyl-3-methylquinoxaline (34), The latter compound is the product of sodium borohydride or Meerwein-Ponndorf reduction of 2-acetyl-3-methylquinoxaline. 

The tetrahydro-l,3-oxazines which contain a free A -hydrogen atom can be iV-acylated and A -nitrosated. - Certain A-substituted derivatives of tetrahydro-l,3-oxazin s can also react with acetic anhydride to form A -acetyl derivatives. > Most tetrahydro-l,3-oxazines add methyl iodide to form quaternary... 

A sulfoxide was obtained by oxidation of 8-[(4-trifluoromethylmercapto-phenyl)methoxy] derivative 358 with 36% H2O2 in AcOH (98MIP7) and by oxidation of l-[2-(4-thiomorfolin-l-yl)acetyl]-7-(3-methoxyphenyl)-A-methyl-A- [3,5-bis(trifluoromethyl)phenyl]ethyl -5-oxo-1,2,3,5-tetrahydro-pyrido[l,2,3-i/ ]quinoxaline-6-carboxamide with 3-chloroperbenzoic acid (01MIP12). A 7-[(4-fluorophenylsulfonyl)methyl] derivative was obtained by oxidation of a 7-[(4-fluorophenylsulfanyl)methyl]perhydropyrido[l,2-u] prazine with 3-chloroperbenzoic acid in CHCI3 (01EUP1074257). 

A) Preparation of 4-Acetyl-7-Chloro-1,2,3,4-Tetrahydro-1-Methyl-5H-1,4-Bemodiazepin-5-one A mixture of 68.5 g (0.37 mol) of 5-chloro-N-methylanthranilic acid, 51 g (0.51 mol) of calcium carbonate, 76 g (0.37 mol) of bromoethylamine hydrobromide and 2.5 liters of water was stirred and heated under reflux for 3 hours. A solution of 23.4 g (0.26 mol) of anhydrous oxalic acid in 250 ml of water was slowly added to the refluxing mixture. The precipitated calcium oxalate was filtered off, and the filtrate adjusted to pH 7 with concentrated ammonium hydroxide. The filtrate was then concentrated to dryness in vacuo and the residue heated on the steam bath with 400 ml of 6 N ethanolic hydrogen chloride until the residue was crystalline. Filtration gave 122 g of N-(aminoethyl)-5-chloro-N-methylanthranilic acid hydrochloride as a solid. 

A mixture of 100 g of this solid and 1 liter of acetic anhydride was stirred and heated under reflux for 1.5 hours and then allowed to stand for 18 hours at room temperature. The excess acetic anhydride was removed in vacuo, and the residue was treated with one liter of water and ice and sufficient sodium bicarbonate to make neutral. The solid was collected, sucked dry on the filter, and triturated with hot ethanol. The ethanol solution on cooling gave 30.8 g of 4-acetyl-7-chloro-1,2,3,4-tetrahydro-1-methyl-5H-1,4-benzodiaze-pin-5-one. 

B) Preparation of 7-Chloro-1,2,3,4-Tetrahydro-1-Methyl-6H-1,4-Bemodiazepin-5-one A mixture of 25.25 g (0.1 mol) of 4-acetyl-7-chloro-1,2,3,4-tetrahydro-1-methyl-5H-1,4-benzo-diazepin-5-one, 33.3 ml (0.1 mol) of 3 N sodium hydroxide and 350 ml of ethanol was heated under reflux for 15 minutes and then concentrated to dryness in vacuo. The residue was treated with 500 ml of water, collected and washed with ethanol to give 20.2 g... 

B. 2-Acetyl-6,l-dimethoxy-l-methylene-l,2,3,4-tetrahydroisoquinoline [Isoquinoline, 2-acetyl-l,2, A,4-tetrahydro-6,7-dimethoxy-l-methylene-]. A 1-1., three-necked, round-bottomed flask equipped with a mechanical stirrer, a reflux condenser topped with a calcium chloride drying tube, and a thermometer is charged with 110 ml. of acetic anhydride, 110 ml. of pyridine, and 45.0 g. (0.22 mole) of the dihydroisoquinoline prepared in Part A. The reaction mixture is stirred and heated at 90-95° for 30 minutes, stored at room temperature overnight, and concentrated by distillation at 50° using a rotary evaporator. The residue is diluted with 20 ml. of ethyl acetate, and another evaporation under reduced pressure gives material that can be crystallized from 75 ml. of ethyl acetate to yield 38.5 41.0 g. (72-77%) of product, m.p. 106-107° (Note 11). 

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