Notes- Pyridoxine N-Oxide

Sakuragi, Taketami; Kummerow, Fred A.

doi:10.1021/jo01089a631

Cited by 14 publications

(16 citation statements)

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“…25, 1973 4293 and 4.30 (9, J = 7 He, CHMe) for the keto amide 5f (56%) along with a corresponding strong peak a t 6 2.18 for AczO. Signals for the enol ester 4f (R3 = Me, 35%) were evident at 6 1.39 (s, CRiIes), 1.96 (6,MeC=C), and 2.14 (s, MeC02C). The amide 7 (R3 = Me, 9%) was tentatively identified by its tert-butyl peak a t 6 1.32 (s, CMea, MeCONH singlet at 6 1.87 apparent as a shoulder), and a low-field acetyl singlet a t 6 2.38 was consistent with a corresponding amount of the mixed anhydride of 8f and acetic acid.…”

Section: Reaction Of Acetyl-n-tert-butylketenimine (2a) and Formicmentioning

confidence: 96%

“…After drying (Na2S04), the solution was evaporated to a small volume and flooded with 80 ml of petroleum ether (bp 40-60"). Seeding, chilling overnight, filtration and drying gave 1.8 g (76%) of tan solid: mp 98-101' (mp 103-104" after recrystallization from CCl4-heptane and EtOAc-petroleum ether); nmr (CDC13) 6 5.64 (br, I), 5.42 (unresolved m, I), 5.16 (unresolved m, 11, 4 41 (unresolved m, I), 1.95 (unresolved m, 3), 1.70 (br, 3), 1.42 and 1.31 (both s, total 18), and 0.97 (d, 6).…”

Section: Signal Was Observedmentioning

confidence: 99%

“…Calcd for CigHs4NnO6: C, 61.58; H, 9.27;N,7.56. Found: C,61.72;H,9.21;N,7.62. Carbobenzoxy-L-serine.-The general procedure directly gave 87% of the ester: mp 77-81" (mp 81-83" after recrystallization from CCl4 or CeHe and petroleum ether); nmr (CDCla) 6 Carbobenzoxy-L-glutamine -The general procedure (extraction work-up) followed by precipitation with CHC13-petroleum ether gave 73% of the ester: mp 98.5-98.6' after drying several days in uacuo (mp 103-106" after recrystallization from CHC1,-petroleum ether); nmr (MeCX) 6 7.37 (s, 5), 5.53 (unresolved m, l ) , 5.12 (6, 2), and 1. 25 (s, 9); [ c Y ]~~D -42.2' (c 1, MeCN).…”

Section: Signal Was Observedmentioning

confidence: 99%

“…A 1ikeIy explanation of the side reaction observed in the N-tert-butyl series would involve N-krt-butyldiacylamides (6) as precursors of the amides 7. Since the diacylamides were not themselves detected in the previous study, they would have to be relatively labile compounds.…”

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confidence: 99%

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N-Acylation during the addition of carboxylic acids to N-tert-butylacylketenimines and the use of the reagent N-tert-butyl-5-methylisoxazolium perchlorate for peptide synthesis

Woodman¹,

Davidson²

1973

J. Org. Chem.

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Diacylamide precursors of amide impurities have been detected in spectral tests of the addition of carboxylic acids to N-tert-butylacylketenimines. Variations in the product distribution with an inefficient acylketenimine in media of differing acidity suggest that diacylamide formation involves a second intermediate adduct that does not convert rapidly to the desired enol ester. A high free acid concentration results in interception of the intermediate to give acid anhydrides. Partial deuterium incorporation a t the vinylic position of the enol esters indicates that intramolecular 0,O-acyl migration is relatively slow for the adducts of N-tert-butyiacylketenimines, and possible substituent influences are discussed. The preparation of p-acyloxy-N-tertbutylcrotonamide enol ester acylating agents from iV-tertbutyl-Gmethylisoxazolium perchlorate succeeds with unprotected hydroxyl groups and the carboxamide function of glutamine. However, amide dehydration was observed in the case of asparagine and competing azlactone formation was detected with benzoylleucine. Crystalline esters were not obtained with Z-Ala-OH, Z-Tyr-OH, and Z-Met-OH. Test couplings have established compatibility of the enol esters with unprotected hydroxyl groups in the amine component but results are not markedly improved relative to iV-ethyl-5-phenylisoxazolium 3'-sulfonate. A new side reaction, condensation of the amine component with the coupling by-product, is shown to be a likely source of impurities in the use of the esters of hindered carboxylic acids. The original zwitterionic isoxazolium salt reagent is much less susceptible to the side reaction.(8) Other workers# have reported that the enol ester of 3,5-diamino-6-chloropyrazine-2-carboxylic aaid similarly gives the Naert-butylamide on treatment with triethylamine, hut a compound assigned the diacylamide structure was obtained with methoxide in polar media. If the latter structure is correct, it remains unclear why fragmentation took place only in the former medium and what special factors account for imide stability in the latter experiment. (9) I<. L. Shepard, W. Halczenko, and A. J. Cragoe, Jr., Tetrahedron Ldt., 4757 (lQ69).ADDITION O F ACIDS TO N-led-BUTYLACYLKETENIMINES J. Ory. Chem., Vol. 38, No. 25, 1073 4289 R1 CMe, + R3C02--la, R1 "Me; % = H b, R1= Ph; & P H c,R1 =Me,C;&-H e, Rl = H &=Me f, Rl 3 Ph; &=Me d, R1= H % H NHCMe, NCMe, %-ON 2 RIYoH I Rz +OCOR3 I NCMe3 J 3 5 6J.

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Section: Reaction Of Acetyl-n-tert-butylketenimine (2a) and Formicmentioning

confidence: 96%

Section: Signal Was Observedmentioning

confidence: 99%

Section: Signal Was Observedmentioning

confidence: 99%

mentioning

confidence: 99%

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N-Acylation during the addition of carboxylic acids to N-tert-butylacylketenimines and the use of the reagent N-tert-butyl-5-methylisoxazolium perchlorate for peptide synthesis

Woodman¹,

Davidson²

1973

J. Org. Chem.

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“…Thus, pyridine N-oxide (40) is reduced to pyridine in fermenting sucrose solutions containing baker's yeast 167 . Similarly, the vitamin B 6 derivative pyridoxine N-oxide (50) has been demonstrated to undergo reduction in yeast incubates 168 . Resting cells of Escherichia coli transform nicotinic acid N-oxide to nicotinic acid 169 ; it has been concluded that certain microbes can adaptively produce enzymes which reduce the N-oxide, so that the nicotinic acid formed can be utilized.…”

Section: Reductionsmentioning

confidence: 99%

N‐Oxidative Transformations ofCNGroups as Means of Toxification and Detoxification

Hlavica

Lehnerer

2009

Patai's Chemistry of Functional Groups

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Introduction Chemical Aspects of the N ‐Oxygenation of the C  N Functionality Occurrence of N ‐Oxygenated C  N Functionalities in Natural and Synthetic Compounds and Biological Activity Metabolic in Vivo and in Vitro Formation of N ‐Oxygenated C  N Functionalities Enzymology of the Formation of N ‐Oxygenated C  N Functionalities Further Transformations of N ‐Oxygenated C  N Functionalities Conclusions

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Chemical and Microbiological Determination of Vitamin B ₆

Storvick

Benson

Edwards

et al. 1964

Methods of Biochemical Analysis

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Notes- Pyridoxine N-Oxide

Cited by 14 publications

References 0 publications

N-Acylation during the addition of carboxylic acids to N-tert-butylacylketenimines and the use of the reagent N-tert-butyl-5-methylisoxazolium perchlorate for peptide synthesis

N-Acylation during the addition of carboxylic acids to N-tert-butylacylketenimines and the use of the reagent N-tert-butyl-5-methylisoxazolium perchlorate for peptide synthesis

N‐Oxidative Transformations ofCNGroups as Means of Toxification and Detoxification

Chemical and Microbiological Determination of Vitamin B ₆

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Notes- Pyridoxine N-Oxide

Cited by 14 publications

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N-Acylation during the addition of carboxylic acids to N-tert-butylacylketenimines and the use of the reagent N-tert-butyl-5-methylisoxazolium perchlorate for peptide synthesis

N-Acylation during the addition of carboxylic acids to N-tert-butylacylketenimines and the use of the reagent N-tert-butyl-5-methylisoxazolium perchlorate for peptide synthesis

N‐Oxidative Transformations ofCNGroups as Means of Toxification and Detoxification

Chemical and Microbiological Determination of Vitamin B 6

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Chemical and Microbiological Determination of Vitamin B ₆