An improved modification of ritter reaction

Tetrahedron Letters, Vo1.30, Printed in Great Britain

AN IMPROVED

A. Garcia

aDepartamento

de Quimica

Universitst

OrgAnica,

TUbingen,

Facultad E-28040

Institut

Lehrstuhl Auf der Morgenstelle

+ .OO

REACTION

de Ciencias Madrid,

Chemie

Quimicas,

Spain

ftir Otganische

Organische

18, D-7&00

0040-4039/89 $3.00 Perqamon Press plc

Alvareza, E. Teso Vilara, b b , L.R. Subramanian

M. Hanack*

Complutense,

1989

OF RITTER

R. Martinez

Frailea,

Universidad

pp 581-582,

MODIFICATION

Martinez*a,

A. Garcia

b

No.5,

Chemie,

II,

Ttibingen 1, Federal

Republic

of Germany

Summary: The reaction of alcohols 1 with trifluoromethane sulfonic anhydride (Tf 0) in dichloromethane in presence 2 of a 2:l excess of nitriles 1 affords the corresponding amides 2 in good yields.

The reaction reaction) and

of alcohols

has been

secundary

amines

The Ritter

amides'. (50-90X

yield)

the yields reaction

only

place

as secondary

presence

of triflic

is carried

hol 1

(IO mmol)

dichloromethane In contrast obtained

reaction

It

has

to form tion

tertiary)

reported

Tf2D

and

alkyltriflate

amides

of anhydride

2

reaction

Advantages

workup.

(20 ml)

initially

it functions

formed well

CR', R2, R3 ,+ H).

Thus

yields

of

The reac

of the alco1

(20 mmol)

NaHCOj

of the amides

thereby

in

solution. are

extending

the

our method are also the mild our method is a convenient

of chlorodiphenylmethylium 4

1 in the

(Table).

solution

saturated

alcohols,

Therefore,

yield

and nitrile

with

the best

and secondary

reaction.

hexachlorantimaniate

alwith

.

methyl-

576

nitrilium

the nitrile 2 with

(Ritter

of primary

,with nitriles

in goad

(IO mmol)

by hydrolysis

Ritter

solvents

the corresponding

1

1 react

a dichloromethane

followed

and easy

that

of the

that

alcohols

alcohols

to give

from primary

to the reaction

of 1,

formed

(and

of Ritter

acid

low in the case of secondary alcohols, while no alcohols 293 . We have now found that primary

to a mixture

in nitrile

been

are

primary

(20 ml)

or reduction

of tertiary

with

anhydride

conditions

ternative alcohols

in the case

sulfuric

for the preparation

has the disadvantage

out by adding

starting

in concentrated method

via the hydrolysis

to the normal

possibilities

nitriles

to be a good

reaction

of the amides

takes

as well

tian

with

proved

the

and

benryl

salt.

-3 proceed formation 581

triflate

Therefore,

7

react

with

nitriles

we presums

that

the

reac-

1.

the

first

via a N-alkylation

of

of nitrilium

2.

salts

by

582

RI Tf,O/CH2C12 R2-!-OH

1

R3 NaH?O,/H,O (50-981) I

Preparation

Table.

R1

R2

of

R3

Amides

R4

H

H

H

C6H5

t-C4H9

H

H

"-C4H9

CH3

H

H

C6iH5

CH3

cH3

H

-C6H12CH3 CH3

CH3

CH3

'gH5 cH3 c6Hs

CH3

CH3

I-Adamantyl

Our of

the

from of

alkyl

RT

5

87

59-60

RT

5

75

76-76

is

Volkswagenwerk

(1) L.I.

Krimen,

0.3.

(2) F.R.

Benson,

("C) or ("C)/torr

Rl

5

90

90-92/1.5

5

82

68-70

-20

2

75

102-103

-20

2

66

103-104

-20

2

50

98-99

RT

2

98

148-149

because 8 , and

the

it

avoids

makes

Ritter

probably

intermediate

Stiftung

mp bp

RT

in

alcohols

unstable

Yield (z )

triflates

alcohols

tertiary

(h)

applicable,

secondary

the

thank

generally unstable

and

yield

We

is

often

primary

tion

CH3

method

Time

Temp.("C)

H

H

2

the

possible

reaction.

due

to

separate

the

the

She

preparation

direct

use

comparatively

competing

of low

elimination

reac

triflate.

for financial

help.

References

(3)

5.

(4)

D.H.R.

(5)

6.~.

(6)

D.N.

(7)

F.

(8)

P.J.

Top,

Trans.

J.J.

I,

Booth,

Orq.

J, Orq.

P.D.

React.

.I. Am.

Ritter,

G. Jaouen, Barton,

Cota,

Chem.

Magnus,

u,

Chem. 46,

J.A.

213 Sot.

78

(1969). 1_1,

4128

(1949).

(

Gabarino,

R.N.

Young,

J. Chem.

SOC-

2101.

1974,

K.O.

Jibodu,

N.F.

Proenga,

J.

Chem.

Sot.

Perkin

Trans.

1067. Kevile, Vedejs,

(Received

Stang,

A. D.A. M.

Perkin

Wang, Engler, Hanack,

in UK 17 November

J.

Chem. M-3.

L.R.

1988)

Sot.

Chem.

Muliins, Subramanian,

J.

Commun.

Orq.

Chem.

Synthesis

1976, 42, 1982,

616. 3109 82.

(1977). m

1, 1983,