Permanganate oxidation of 4-thiouracil derivatives. Isolation and properties of 1-substituted-2-pyrimidone-4-sulfonates

Tetrahedron

Lattera

No.9,

ppm 755-758,

PERMANGANATE ISOLATION

1969.

OXIDATION

AND PROPERTIES

of Pharmaceutical

{Received

pyrimidines potassium

studies

and M.

University received

can be rapidly

(KMn04)

nucleoside

DERIVATIVES.

of Tokyo,

publication

oxidation

of nucleic

nucleophilic

acids,

here

RNA as a “minor” 4-sulfonate.

substitution

reactions

Japan 1969)

we have found

with dilute

We report

in transfer

corresponding

Tokyo,

21 January

oxidized

pH and 0°C (1).

to give

various

Bunkyo-ku,

in UK for

to be present

with KMn04

can undergo

in h-eat Britain.

Yano

and selectively

at neutral

now known

oxidized

that the sulfonate at room

acids

permanganate

readily

OF 4-THIOURACIL

on the permanganate

in nucleic

a pyrimidine is very

Sciences,

in Japan 8 January 1969;

In our recent

Printed

OF l-SUBSTITUTED-2-PYRIMIDONE-4-SULFONATES

H. Hayatsu Faculty

Pergamon PI-em.

that

aqueous that 4-thiouridine, constituent

It is further

shown

in aqueous

solution

temperature. 5

;s Y?lN k

70; -litl!L/, H200/’

N’

Q

4 A

I -CH2

(a-series),

R’:

-OH (IIIa and b), (VIIa),

m-m

- ribofuranosyl -NH2

I

OS Ii

II

R:

-a

R’ \

(IVa

(b-series)

and b),

-NHCH2

-NHCH(COOH)CH2CgH5

(Va),

-N(CH3)2

(VIaI,

(VIIIb)

Results

We will compound

first

describe

of 4-thiouridine,

the experiments

carried

and then describe

out with 1-methyl-4-thiouracil,

the results

755

obtained

with 4-thiouridine.

a model

(21,

No.9

756

Experiments Permanganate KMn04

(2 equivalent

acetic

The

acid.

potassium

salt

C5H5N204SK: K,

oxidation

17.17.

phoresis

of Ia.

moles

Ia (3) in H20

was

complete

and recrystallized

from

C,

26. 27; H, 248-252”

of the sulfonate

1-Methyl-4-thiouracil

2. 21; N,

(dec.

1.

IIa was

The

H20-ethanol 12. 28; K,

82 %.

17.13.

sulfonate

Found:

addition

maintained

isolated

needles. C,

Anal.

26. 39; H,

315 (5,600),

xpHn7243

behaves

as an anion

compound

of 50 mM

by addition

IIa was

to colorless

(~):7ir~z

This

by dropwise

the pH being

in 15 min.

UV, hrnp

(Ia)

was oxidized

to Ia) at pH 7 and O”C,

reaction

m.p.

The yield

with

of aq.

as its Calcd

2. 31; N,

for 12.31;

(approx.

200).

in paper

electro-

at pH 7.

Reactions summarized aqueous

of the sulfonate in Table

solution

I.

IIa with nucleophilic

It can be seen

by a variety

imidazole

and hydrogen

analytical

methods

when thealatters

including

were

Table

Experiment number

I.

elemental

analysis,

UV spectra,

Reactions

R.eaction

such

group

as ammonia,

All of the reaction

available,

The

that the 4-sulfonate

of nucleophiles,

sulfide.

reagents.

products

reactions

carried

is readily

replaciable

methylamine,

were

mixed

melting

and NMR

spectra.

a)

0.1

N HCl,

5.6

% NH40H,

30 min 30 min

15 % aq.

CH3NH2,

4 hr

18 ‘% aq.

(CH312NH,

4 hr

test with authentic

samples

(IIa)

m.p.

(“Cl

IIIa

72

235-7

(dec.

11;

IVa

93

301-2

(dec.

1

Va

84

181-3e)

Via

I”6

181-2e’ 265-7

(dec.

1

195-6

(dec.

Id1

Imidazole (1. 5 equivalent to IIa) in H20, pH 8. 2, 3 days

VIIab)

H2S in H20,

Ia

30 min

dimethylamine, by various

Yield of the crystalline product isolated (‘%)

Product

in

characterized

of l-Methyl-2-Pgrimidone-4-Sulfonate

conditions

out are

91

Amount of the starting material a) All of the reactions were performed at room temperature. used was: 0. 50 g. in experiments No. 1 and 2; and 1. 0 g. in experiments No. 3 to 6. b) UV absorption of this new pyrimidine derivative is as follows: Amp

(~1; ~2~:

238,

303 (8,710,

9, 260),

d) Reported m.p.: 294-6” 237-8” (4). 1” for Va and 178-9” for Via (5).

Experiments

for

7?2;

232,

268 (8, 300,

IVa and 193-4”

with 4-Thiouridine

(Ib)

for

4, 310).

Ia (3).

cl Reported

e) Reported

m. p.

m. p.

: 180-

:

757

No.9

Rate

of oxidation.

4-thiouridine from

(3) was

the start

in absorption oxidation

much

and uridine

is oxidized

This

observation

following

Properties

scheme,

of uridine

as judged

with little

success

Therefore

the crude

In neutral alkali

quantitative oxidation placed

followed

alanine.

example Thus,

after

added

to the oxidation

ture.

Paper

group

directly

IIb is stable

at least

with ammonia, of reaction

of the sulfonate

chromatographic

oxidation

a small

40 % conversion

met

to give

uridine.

but in acid

and

for

complete

3 hr; at pH 12, effected

formed

of 4-thiouridine

analysis

5 %)

this material

temperature,

Ilb with a nucleophile

allowed

(ca.

IIb

reactions.

When the last were

sulfonate

amount

to hydrolysis

was actually

and the reaction showed

The

with 2 equivalent

and the sodium

required

at pH 4,

and uridine

of 4-thiouridine.

KOH

at purifying

10 hr at room

2 hr.

+

contained

to subsequent

at pH 1. 5 for

at 330 rnp

the sulfonate.

was treated

15 min.

the time

to a

it was concluded

of 1 mole

2 Mn02

in IIb is susceptible

to uridine

the permanganate

density

is indeed

but attempts

for

of KMn04

oxidation:

+

material

at pH 2, 10 min;

cytidine

in optical

4-Thiouridine

Thus,

to uridine.

treatment

mixture

This

with which

(1).

amounts

the oxidation

and 0°C for

submitted

of 4-thiouridine

by acid

by treatment

Another

318 rnp.

is as follows:

conversion

IIb.

in absorption

that the ease

10 min * at pH 7 and O”C,

for this

by the decrease

8 % decrease

varying

the decrease

RS03K

buffer)

only

that the product

in 6 min

to the permanganate

to that of uridine

for

Thus,

as judged

be noted

By adding

chromatography**,

hydrolysed

temperature

equal

_____)

the sulfonate

IIb was

solution,

it is rapidly

at room

by paper

It should

is proposed

of the sulfonate

oxidized

gave

at pH 6. 7 and O”C,

or uridine.

susceptible (11,

is utilized

with the idea

UV, AL:,’

since

nucleosides

of KMn04

at pH 7 (phosphate

as a powder.

the most

to stand for

2 KMn04

and reactions

completely

and measuring

therefore, +

was

to be roughly

mixture

of 0. 1 mM KMn04

than thymidine

consumption.

is in agreement

of KMn04

isolated

shown

2 moles

RSH

rapidly

unaffected.

of 4-thiouridine

reaction

amount

virtually

the reaction

conditions

thymidine,

of permanganate

allowing

more

pyrimidine

was

, in this reaction,

that

whereas

has been

solution

reaction

4-thiouridine

the “major”

Stoichiometrg

after

oxidized

at 330 m(r,

at 270 mp,

bufferized

the mild

of the reaction,

among

cytidine

Under

to proceed

hydrolysis

20 min.

A

by permanganate acid in 9/l

treatment

was re-

ratio.

is that with L-phenyl-

at pH 7, L-phenylalanine for

1 hr at room

of 4-thiouridine

* Almost identical results were obtained when the time of standin was elongated 8 (86:14, v/v). ‘**- The Rf value of IIb is zero using solvent system: n-butanol-H2

was

tempera-

into N-(1-4-D-

to 30 min.

758

No.9

ribofuranosyl-2-oxo-4-pyrimidinyl)-L-phenylalanine

(VIIIb)

(6).

Discussion 4-Thiouridine (2, 3), occurs

has been

osmium

tetroxide

in the iodine

understood.

oxidation,

tuted pyrimidine temperature,

result,

Studies

chemical

these

lines

in the other

oxidizing

(2).

oxidations

demonstration

agents

Disulfide have

as iodine

formation not been

of sulfonate

intermediate

for

The

can be carried

are

(pK,,

out that the ease

selective along

of the products

as imidazole

be pointed

permit

be a useful

and nucleotides.

and the yields

It should

(8) and periodate

is the first

therefore,

of type II would

such

peroxide

with such

well

formation

derivatives.

nucleosides

even a weak base

oxidizable

but the mechanisms

of 4-thiouracil

The 4- sulfonate

to be readily

(71, hydrogen

The present

in the oxidation

could

known

generally

6.9)

high.

can undergo

with which

modification

reaction

of various

4-thiouridine

interest

at low

is that

of the sulfonate

is oxidized

residues

4- substi-

out in water

Of special

replacement

of 4-thiouracil

are in progress

synthesis

group.

with KMn04

in tRNA.

in our laboratory.

Acknowledgements We thank Prof. work

was

T.

supported

Ukita for

by the Grant

his encouragement from

throughout

the Ministry

the present

of Education

investigation.

This

of Japan.

References (1) H. Hayatsu (2) M.

and T.

N. Lipsett,

(3) J. J.

Fox, A.

D. V.

Bendich Hilbert

Ukita,

J.

Biol.

Biochem. Chem.,

Praag.

and G.

I. Wempen, B.

Brown,

(4) G.

E.

(5) W.

Szer

and D. Shugar,

Acta

and J.

J. Med.

(6) T.

Ueda

(71 K.

Burton,

(8) K.

H. Scheit,

and T. B. Johnson, J. Fox,

Biochem. Biochim.

Biophys.

240.

J.,

Res.

Commun.,

I. L.

Doerr,

J. Am.

Chem.

J. Am.

Chem.

Biochim.

Polon.,

Chem.,

S,

L. Sot., Sot.,

-13 (2),

697 (1963).

104. 686 (1967). Biophys.

Acta,

2,

556 (1967).

3975 (1965).

166,

285 (1968).

Cheong, g,

J. E.

Knoll,

178 (1959).

52, 2001 (1930). 177 (1966).

M.

L.

Eidinoff,