AU671358B2 - Process for preparing organic carbamates - Google Patents

Abstract

A process has been found for the preparation of organic carbamates from a basic amine, carbon dioxide and an alkylating agent, the process being characterised in that the amine is first reacted with carbon dioxide in the presence of one or more basic compounds of the elements lithium, sodium, magnesium, potassium, rubidium, strontium, caesium, barium and/or ammonium, and subsequently adding the alkylating agent.

Description

Gai/m-p514E PROCESS FOR PREPARING ORGANIC CARBAMATES The present invention relates to a particularly advantageous and easily to be carried out process for preparing organic carbamates from amines, carbon dioxide and an alkylating agent.

It is known that diethylamine can be converted to carbamates by means of alkyl halides under CO 2 pressure (see for example Chem. Letters 1984, 1571-1572).

S"Suitable reaction conditions are, for example, 40 atm pressure, 70 0 C and 48 hours reaction time. Yields are in the range from 6 to 53%. Disadvantages are the expense of working under pressure, the long reaction times and the often only small to very small yields. In Bull. Chem. Soc. Jap. 62, 1534 (1989) it is stated that in this method use of more than 5% by weight of solvent (for instance dimethylformamide or dimethyl sulphoxide) leads to losses in yield.

The reaction of a weakly acid amine 2-alkylindole) with n-butyllithium and 15 carbon dioxide gives the corresponding lithium carbamate. which can be alkylated in the amine part, but not in the carbamate group, by alkylting agents in the presence of a strong organic base t-butyllithium) (see for example J. Am.

Chem. Soc. 108, 6808-6809 (1986)). This is accordingly not a process for preparing organic carbamates, but for alkylating carbamates in the amine part.

Other ct,3-unsaturated, i.e. weakly acidic electrophilic) amines, their metal salts and the metal carbamates obtainable from them, can be converted to organic carbamates without catalysts or with basic catalysts (see for example US-A 3,147,262, US-A.3,299,076, FR-A-2 444 030 and J. Org. Chem. 54, 2425 (1989)).

Those skilled in the art would rule out the applicability of such reactions of weakly acid amines to typical basic and nucleophilic amines, since, taking into account J. Am. Chem. Soc. 108, 6808-6809 (1986) (see above) and J. Chem. Soc.

Chem. Commun., 1979, 797, alkylation is expected in the amine part and not in the carbamate group.

Le A 29 700-FC

L

There are also processes for preparing organic carbamates from amines, carbon dioxide and alkylating agents or from metal carbamates and alkylating agents, in which environmentally unfriendly and/or costly compounds must be used, such as silver carbamates, zinc alkyls, palladium compounds and crown ethers (see for example, Japanese Published Specification 49-81371), Japanese Published Specification 51-113852, Bull. Chem. Soc. Japan 61, 2613 (1988), J. Chem. Soc.

Dalton Trans. 1989, 1007 and EP-A 477 159). Such processes are not very suitable for commercial application.

Finally, the preparation of organic carbamtes from amines, carbon dioxide and alkyl halides in the presence of stoichiometric or excess amounts of strong organic bases, for example diazabicyclo(5.4,0)-undec-7-ene DBU), has also become known (see for example EP-A 511 948), Chemistry Express 1, 224 (1986)). The large amounts of organic bases required, which are expensive to prepare, difficult to separate and difficult to dispose of, the use of specific solvents and the extensive exclusion of water make this process also unattractive for commercial application. Furthermore, strong bases such as DBU tend to give a multiplicity of reactions, for example eliminations, which increases the probability of forming byproducts (Oediger et al., Synthesis 1972, 591).

In EP-A 511 948 it is specifically indicated that good yields are only obtained 20 with large excesses of alkyl halides. This is naturally very disadvantageous from an economic point of view.

The catalytically forced addition of alkenes, alkines, carbon dioxide and amines to form carbamates is likewise known Molecular Catalysis 74, 97 (1992)).

However the alkylating agents used here have their functionality altered, which is not the case in this invention.

A process has been found for preparing organic carbamates from a basic amine, carbon dioxide and an alkylating agent, which is characterized in that the amine is first reacted with carbon dioxide in the presence of one or more basic compounds of the elements iithium, sodium, magnesium, potassium, calcium, rubidium, strontium, caesium, barium and/or of ammonium and the alkylating agent then added.

Le A 29 700-FC -2- -3 In the process of the invention a wide variety of basic amnines can be used, for example those of the formula (1) N A- N 42/_

A

M n in which R1, R? and Wi are the same or different and each represent hydrogen or one of the following radicals in monovalent form: C 1

-C

30 -alkyl, C 3

-C

30 -alkenyl, C 3

-C

30 alkinyl, C 3

-C

1 2 -Cycloalkyl, C 5

-C

1 2 -cycloalkenyl, C 8

-C

12 -Cycloalknyl, C 6 -G 14 -aryl,

C

5

-C

13 -hetaryl having up 3 oxygen, sulphur and/or nitrogen atoms in the ring system, C 7

-C

20 )-aralkyl, C 9

-C

20 -aralkenyl, C 9

-C

20 -aralkinyl, C 7

-C

20 -alkaryl, C 8 2 alkenearyl or C 8

-C

20 -alkinearyl, which can optionally be substituted from one to five times by O-C 1

-C

12 -alkyl or

-C

6 -Cl 0 -aryl, NI-I 2 NH-Cl-C 12 -&Ikyl or -C 6 -Cl 0 -aryl, N(CI-C 12 -alkyl or aryl) 2

COO-C

1

-C

1 2 -alkyl or COO-C 6 -Cj 0 -aryl, CONH 2

CONH-C

1

-C

1 2 -alkyl,

CON(C

1

-C

12 -alkyl) 2 halogen, OP(O-C 1

-C

12 -alkyl or -C 6

-C

1 0 -aryl) 2 Si(C 1

-C

1 2 alkyl and/or C 6 -Cl 0 -aryl) 3 Si(O-C 1

-C

12 -alkl and/or C 6

-C

10 -aryl) 3 Si(C 1

-C

12 -alk or -C 6

-C

1 0 -aryl)(O-C 1

-C

1 2 -alkyl and/or O-C 6 -Cj 0 -aryl) 2 Si(C 1

-C

12 -alkyl and/or

C

6

-C

1 0 -aryl) 2

(O-C

1

-C

1 2 -alkyl or O-CCC 10 -aryl), OS(C 1

-C

1 2 -alkyl or C 6

-C

1 O-aryI), 0 2

S(C,-C,

2 -alkyl or CC 1 0 O-aiyl), CHO, CN, C(O-C 1

-C

1 2 -alkyl or -C 6 -Cj 0 -aryl) 2

OC(CI-C

1 2 -alkyl or C 6 -Cl 0 -aryl), N2, C3' OCF2H, OCFH 2 0CF 2 3 20 OCH 2

CF

3

OCO(C

1

-C

12 -alky' or C 6 -Cl 0 -aryl), HNCO(C 1

-C

1 2 -alkyl or aryl), OP(C 1

-C

1 2 -alkyl or C 6

-C

1 0 -aryl) 3 OP(O-Cl-Cl 0 -alkyl or -C 6

-CI

0 -aryl) 2

(C,-C

12 -akl or C 6 -Cl 0 -aryl) and/or can optionally be interrupted by oxygen or sulphur atoms or by N(C 1 -C'2alkyl or C 6 -Cl 0 -aryl) groups, 25 where R 1 and R 2 or W? and W 4 in each case together, can also be one of the above-defined radicals, albeit then in divalent form,

I_

or R 3 and R 4 can together be a from 3- to 10-membered alkyl ring, which can optionally be substituted with one or two Ci-Clo-alkyl groups and/or optionally be interrupted by one or two oxygen, sulphur and/or nitrogen atoms, A is hydrogen or a radical as defined for R 1 although in divalent form, m is zero or an integer from 10 to 10 and n is an integer from 1 to with the provisos that a) R 1

R

2

R

3 and R 4 are not radicals which contain an isolated a,p multiple bond, b) in the case of m zero, at least one of the radicals R 2

R

3 and R 4 is hydrogen, c) in the case of A hydrogen, m is zero and d) in the case of A hydrogen, R 3 and R are not simultaneously hydrogen.

The proviso a) essentially excludes enamines.

15 Some, not exhaustively listed examples of alkyl groups, including those in compound radicals, are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl and hexadecyl, :which can each be straight-.chain or branched and/or optionally be substituted by fluorine.

20 Some, not exhaustively listed examples of alkoxy groups, including those in compound radicals, are methoxy, ethoxy, propyloxy, butyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy and dodecyloxy, which can each be straight-chain or branched and/or optionally be substituted by fluorine.

S Le A 29 700-FC 4 f r '\S'FF\kC

L

Halogene means fluorine, chlorine, bromine or iodine.

Some, not exhaustively listed examples of hetaryl groups are pyrazolyl, imidazolyl, 1,2,4-triazolyl, pyrrolyl, furanyl, thienyl, thiazolyl, oxazolyl, pyridinyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, indolyl, benzothienyl, benzofuranyl, benzothiazolyl, benzimiidazolyl, pyrazolylmethyl, imidazolylmethyl, 1,2,4-triazolylmethyl, pyrrolylmethyl, furfuryl, thienylmethyl, thiazolylmethyl, oxazolylmethyl, pyridinylmethyl, pyrimidinylmethyl, triazinylmethyl, quinolinylmethyl, isoquinolinylmethyl, quinazolinylmethyl, indolylmethyl, benzothienylmethyl, benzofurfuryl, benzothiazolylmethyl or benzimidazolylmethyl, where optionally each of these groups can be mono- to trisubstituted by the same or different substituents, for example by fluorine, chlorine, bromine, methyl, ethyl and/or tert.-butyl.

The process of the invention can also be carried out using polyamines which contain, for example, 21 to 500,000

R

5 N -groups 2R

R

where at least one of these groups R' is hydrogen and R 1 and R 2 are otherwise as defined in formula but where R' and R 2 cannot together be a divalent radical.

Such polyamines can, for example, have molecular weights of from 500 to 3,500,000.

Preferred amines are those of the formula in which R 2

R

3 and R 4 are the same or different and are each hydrogen or one of the following radicals in monovalent form:

C

1

-C

14 -alkyl, C 3 -Co 10 -alkenyl, C 3 -Co 1 0 -alkinyl, C 3

-C

12 -cycloalkyl, C 5

-C

7 cycloalkenyl, C 6 -Clo-aryl, Cs-Clo-hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system C 7

-C

12 -aralkyl or C 7 -Clo-alkaryl, which can optionally be substituted one to five times by O-C 1

-C

6 -alkyl or -C6-Cloaryl, NH2, NI-C 1

-C

6 -alkyl or -C 6 -CIo-aryl, N(C-C 6 -alkyl or -C 6

-C

1 o-aryl) 2

COO-C

1

-C

6 -alkyl, COO-C 6

-C

10 -aryl, CONH-Cl-C 6 -alkyl, CON(C 1

-C

6 -alkyl) 2 Le A 29 700-FC 5 OS(Ci-C 6 -alkyl or phenyl), 0 2 S(Ci-C 6 -alkyl or phenyl), CHO, CN, OC(CI-C 6 alkyl or phenyl), NO2, CF3, OCF3, OCFH, OCFH2, OCO-(C 1

-C

6 -alkyl or phenyl) or HNCO(Ci-C 6 -alkyl or phenyl), and/or can optionally be interrupted by oxygen or sulphur atoms or by N(CI-C 6 alkyl or phenyl) groups, where R 1 and R 2 or R 3 and R 4 in each case together, can also be one of the above-defined radicals, albeit then in divalent form, or R 3 and R 4 can together be a from 5- to 7-membered alkyl ring, which can optionally be substituted with one or two C 1

-C

6 -alkyl groups and/or optionally be interrupted by an oxygen or sulphur atom or an N(C-C 6 -alkyl or phenyl) group, A is hydrogen or a radical defined as preferred for in divalent form, m is zero or an integer from 1 to 5 and n is an integer from 1 to with the provisos that

R

2

R

3 and R 4 are not radicals which contain an isolated a,P multiple bond, in the case of m zero, at least oce of the radicals R 2 R and R 4 is :hydrogen, Sc') in the case of A hydrogen, m is zero and 20 in the case of A hydrogen, R and R are not simultaneously hydrogen.

U*

Particularly preferred amines are those of the formula in which R 1

R

2

R

3 and

R

4 are the same or different and are each hydrogen or one of the following radicals in monovalent form: S"Le A 29 700-FC -6- I methyl, ethyl, n-propyl, i-propyl, butyl, cyclohexyl, phenyl, pyrazolyl, imidazolyl, pyrrolyl, furanyl, thienyl, pyridinyl, quinolinyl, isoquinolinyl, quinazolyl, indolyl, benzyl, tolyl and xylyl, which can optionally be mono- or disubstituted by methoxy, ethoxy, phenyl, CHO, CN, carboxymethyl, carboxyethyl, OCF 3

OCF,

2 I or NO 2 which can optionally be interrupted once or twice by an oxygen atom or an Nmethyl, N-ethyl or N-phenyl group, .where R' and R2 can together also be one of the above-defined particularly preferred radicals, although in divalent form, A is hydrogen or one of the particularly preferred radicals as defined for R'I although in divalent form, m is zero, 1 or 2 and n is 1 or 2, with the provisos as given above for the preferred amines.

15 Some individual amines are: dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamnine, di-s-butylamine, di-t-butylamine, di-n-pentylamine, diamylamine, di-i-amylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, dipentadecylamine, dihexadecylamine, diheptadecylamine, dioctadecylamine, dicyclohexylamine, dibenzylamine, diphenylamine, diallylamine, N-methylaniline, Nethylaniline, N-propylaniline, N-cyclohexylaniline, morpholine, morpholine, piperidine, pyrrolidine, thiomorpholine, N-methylpiperazine, N-ethylpiperazine, tetrahydroisoquinoline 4-piperidone, and the methyl, benzyl and ethyl esters of the following amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, pipecotinic acid, nipecotinic acid, isonipecotinic acid, 4-piperidone-3carbonic acid, as well as compounds of similar structure of the last example given in EP 541,407 or TAN-amines (see EP 511,948), Le A 29 700-FC

I

glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, tbutylglycine, ornithine, norleucine and sarcosine.

The carbon dioxide used in the process of the invention can be the usual commercial product, optionally also so-called dry ice. Isotopically enriched carbon dioxide, for example containing 13C and/or 14 C, can also be used, in particular for specific purposes, such as analytical or diagnostic applications or where the products which can be prepared are to be used in such applications.

A wide variety of alkylating agents can be used in the process of the invention, for example compounds of the formula (II) 7

-Z)

0 B (II), X-R B(

(R

6 .i in which

R

5

R

6 and R7 are the same or different and are each one of the following radicals in divalent form: C 1

-C

30 -alkyl, C 4

-C

12 -cycloalkyl, C 3

-C

30 -alkenyl, C 5

-C

12 -cycloalkenyl, C 3

-C

30 -alkinyl, C8-C 12 -cycloalkinyl, C 7

-C

20 -aralkyl, C 8

-C

2 0 -aralkenyl,

C

8

-C

20 -aralkinyl, C8-C 20 -alkenaryl, Cg-C 20 -alkinaryl, C 5

-C

13 -alkenehetaryl or Cs-C 13 -alkinehetaryl, the latter two each having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, where chains in the molecules can be linear, branched and/or optionally interrupted by oxygen, sulphur, N(C 1

-C

12 Or C 6 -C1 0 -aryl), CO, COO, SO, SO 2 or SO(0)O or OP(C 1

-C

1 2 -alkyl or C 6

-C

10 -aryl) groups, where the groups R 6 -Y and R 7 -Z can also be hydrogen and in this case R 5 can optionally be additionally substituted by COO(C 1

-C

1 2 -alkyl or C 6 -Co 1 0 -aryl),

O-C(O)-(C

1

-C

1 2 -alkyl or C 6

-C

1 0 -aryl), CON(C 1

-C

12 -alkyl or C 6

-C

10 -aryl) 2

(CH

2 1

-C

12 alkyl or C 6 -Cl 0 aryl), C 6

-C

1 0 -aryl, C 5

-C

11 -hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, O(C 1

-C

12 -alkyl or C 6 -Clo-aryl), N(C 1

-C

12 -alky or C 6

C

1 0 -ary) 2

OP(OC-C

1

-C

1 2 -alkyl or C6-C]o- Le A 29 700-FC 8 aryl) 2 Si(O-C 1

-C

12 -alkyl or -C 6 -Clo-aryl) 3 Si(C 1

-C

12 -alkyl or C 6 -Co 1 -aryl) 3 or halogen, o and p independently of one another are each zero or 1, B is not present if o p zero, in the case of p 1 and o zero, B is one of the following radicals in divalent form: CH 2

N(C

1

-C

12 -alkyl or C 6

-C

10 -aryl), OP(C 1

-C

12 -alkyl or C 6 -Clo-aryl), phenyl, naphthyl, (CH2)q with q 2 to 30 or (CHl 2 )-M-(CH2) s with r and s being the same or different and each 1 to 20 and M an oxygen or sulphur atom or an SO 2 or N(C,-C 12 -alkyl or C 6 -Co 1 -aryl) group, 10 in the case of p 1 and o 1, B is one of the following radicals in trivalent form: CH, N, phenyl or naphthyl and X, Y and Z independently of one another are each a leaving group.

Alkene and alkine radicals may be once or several times unsaturated.

Suitable leaving groups X, Y and Z are, for example, halogen such as fluorine, chlorine, bromine and iodine, sulphonate such as aryl- and perfluoroalkylsulphonate, monosubstituted diazo and monosubstituted nitrato, and those additionally given in J. March, Advanced Organic Chemistry, 3rd Ed., John Wiley Sons, New York 1985, pp. 310-316. Chloromethylated aromatic polymers, such as chloromethylpolystyrene, having molecular weights of, for example, from 1000 to 1,000,000 are also suitable.

Preferred alkylating agents of the formul (II) are those in which R 5

R

6 and R 7 are the same or different and are each one of the following radicals in divalent form: C 1

-C

20 -alkyl, C 5 -Cg-cycloalkyl, C 3 -Clo-alkenyl, C 5 -Cg-cycloalkenyl, C 3 alkinyl, C 7 -C1 4 -aralkyl, Cg-C 15 -aralkenyl, C 8

-C

15 -aralkinyl, Cs-C 1 4 -alkenaryl,

C

5 -Clo-alkenehetaryl or C 5 -Clo-alkinehetaryl, the latter two having each up to 2 sulphur and/or nitrogen .ooms in the ring system, Le A 29 700-FC where chains in the molecules can be linear, branched and/or optionally interrupted by oxygen, sulphur, N(C 1

-C

1 ,-alkyl or C 6

-C

1 o-aryl), CO, SO or SO, groups, where the groups R 6 -Y and RF-Z can also be hydrogen and in this case R5 can optionally be additionally substituted by COO(C 1

-C

6 -alkyl or phenyl), CON(Cl-C6-alky), C6-Clo-aryl, CH2-O-(-C(0)-CI-Cl2alkyl), Cs 5

-C

8 -hetaryl having up to 2 sulphur and/or nitrogen atoms in the ring system, OC 1

-C

6 -alkyl, N-C 1

-C

6 -alkyl or halogen, .B is not present if o p zero, S 10 in the case of p 1 and o zero, B is one of the following radicals in divalent form: CH 2

N(C

1

-C

6 )-alkyl or phenyl), phenyl, naphthyl, (CHq2)q with q 2 to or (CH 2 )r-M-(CH 2 )s with r and s being the same or different and each 1 to and M an oxygen or sulphur atom or an SO, or N(C 1

-C

6 -alkyl or phenyl) group, :i in the case of p 1 and o 1, B is as defined above and X, Y and Z independently of one another are each a leaving group.

Possible alkylating agents include tri(C 1

-C

1 9 -alkyl) phosphites and also acetates and aminal esters of dimethylformamide, each having a total of up to 10 carbon atoms.

Possible alkylation agents include further: ac-D-Gllucopyranosyl bromide tetra acetate, a-D-Glucopyranosyl bromide tetra benzoate, 2,3,4-Tri-o-acetyl-a-D-xylopyranosyl bromide, 2,3,4,6-Tetra-o-acetyl-a-D-xylopyranosyl bromide, 2,3,4,6-Tetra-o-acetyl-ac-D-glucopyranosyl bromide, Methyl-2,3,4-tri-o-acetyl-1-bromo-1-deoxy--D-glucopyranuronate, ac-D-Galactopyranosyl bromide tetraacetate, Acetobromo-a-D-galactose, 2,3,4,6-tetra-o-acetyl-a-D-galactopyranosyl bromide, Le A 29 700-FC 10 Methyl -(2,3,4-tri -o-acetyl-oc-D-glucopyranosy1-b romide)-uronlate, 1-a.-bromo gluconic acid 2,3,4-tri-o-acetyl methylester, 1 -cx-b romo gluconic acid 2,3 ,4-tri-o-acetyl ethylester, Acetobromo cellobiose, ct-bromo hepta-o-acetyl maltose and 2,3 ,6-tri-o-acetyl-4-o(2,3 ,4,6-tetra-O-acetyl-cx-D-glucopyranosyl) glucosyl bromide or similar halogen/oxygen acetals which are described in Houben-Weyl, Methonn der Organischen Chenie, Band El4a/3, page 1-136 and 621-1075 as well as halogen/sulfur or halogen/nitrogen acetals, described on pages 142-202 and 203t0 620.

In addition to these reagents suitable for the claimed reaction one can prepare C- (3 )-chloro (or bromo or iodo)- 1,3 -dihydro-2H- 1,4-benzodiazepin-2-ones as given in Kova6 et al., 3. Heterocyclic Chem, 16, 1449 (1979), p. 1452 method A or B and *0react these with CO 2 and amines as claimed to yield, e.g. Camazepamn dimethyl carbamic acid 7-chloro-2,3 -dihydro- 1-methyl-2-oxo-5-phenyl- 1H-benzodiazepin-3 yl ester (see Merck Index I It" ed., 1732).

Particularly preferred alkylating agents are those of the formula (III)

R

5 1 (11I), in which 20 R 5 is one of the following radicals ini m-onovalent form: C 1

-C

20 -alkyl, C 4

-C

12 -cycloalkyl, C 3

C

30 -alkinyl, C 7

-C

20 -aralkyl, C 8

-C

20 -aral kenyl, C 8

-C

20 -alkenaryl,

C

8

-C

20 -alkinaryl, C 5

-C

13 -alkeneiiietaryl or C 5

-C

1 3 -alkinehetaryl, the latter two each having up to 2 oxygen, sulphur and/or nitrogen atoms in the ring system and X is a leaving group, and also the following individual compounds: The bromides, iodides, toluenesulphonates and mesylates of the following radicals: methyl, ethyl, propyl, i-propyl, allyl, n-butyl, i-butyl, s-b~ityl, t-butyl, pentyl, hexyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, docosyl, tricosyl, cyclopropylmethyl chloride, cyclopropylrnethyl mesylate, benzyl chloride, benzyl bromide, benzyl iodide, b enzyl p-tolyl sul phonate, benzyl m esylate, 2-(cloromethiyl)-naphithalene, 3- (chloromethyl)-naphthatene, the chloride, toluene suiphonate and mesitylate of 9- Le A 29 700-FC 11 Ii ucrenyl methyl, ci nnamyl chloride, p-methoxybenzyl chloride, m- and p-nitrobenzyl chloride, p-bromobenzyl chloride, m- and p-chlorobenzyi chloride, 9anthrylmethyl chloride, methyl chioromethyl ether, ethyl chioromethyl ether, butyl chi oramethyl ether, octyl chioromethyl ether, N-chloromethylphthali mide, 2,2,2tri chl oro- 1, 1, 1 -dimethyl ethyl chloride,o-, m- and p-chloromethylbenzyl chloride, monochioroacetone, ethyl chioromethyl ketone, propyl chioromethyl ketone, phenyl chioromethyl ketone, p-nitrophenyl chioromethyl ketone, methyl and ethyl chi oroacetate, methyl and ethyl bromoacetate, p -(chl oromethyl) -polystyrene, Merrifield's peptide resins, t-butyl 4-chloroacetoacetate, 2,5- 2,6- and 3 ,4-di chl oz~obenzyl chloride, (3 chl oropropyl)-4 -methyl pip erazi ne, 1 ,2-dichloroethane, 1,3 -dichloropropane, 1 ,4-di chlorobutane, 1 ,5-dichloropentane, dichioromethyl ether, 2,4-di clloro-2-butene, 1 ,4-dichloto-2-butine, di-( 1-chloroethyl) thioether, chioromethyl t-butyl ketone, 3-(chloromethyl)-heptane, chioroacetonitrile, 4chi orobutyronitrile, chioroacetaldehyde, epiciorohydrin, isoamyl chloride, 6chlorohexyl isocyanate, 2-isocyanatobenzyl chloride, triethoxychioromethylsilane, methyl and ethyl 1 -chloropropionate, crotyl chloride, 1 -dimethylamino-2-chloroeth ane, I ,2-di chl oro-2-propene, 1 -chloro-2-methyl -2-propene, chloroacetamidobenzene, I -ch iloroacetamido-4-chlorobenzene, N,N-diethylchloroacetamide, 2-chloro- ~.*ethyl p-chiorophenyl ketone, methyl, ethyl, propyl, n-butyl and t-butyl esters of 2or 4-chloroacetic acid, cx-2,4-trichloroacetophenone, cliloromethyl phenyl and tolyl sul phone, 3 -chloropentane dione, diethyl chloroacetamide, dimethyl -2-chl oroacetaid.e, ethyl -c-chiorophenylacetate, 2-chloro-rnalonic acid diethyl ester and 2chl oro-m al oni c acid dimethylester. Also methylene chloride, methylene bromide and cloro-bomo-methane are suitable alkylating agents.

Particularly preferred sulphonate radicals X, Y and Z are p-toluen esul phonate, pb romob enzen esul phonate, p-chlorobenzenesulphionate, p-nitrobenzenesul phonate, in ethan esul p honate, trifluoromethanesui phonate, nonafluorobutanesulphonate, 2,2,2-tn fi uoroethanesulphonate and benzal sul phonate.

Alkylating agents containing sulphonate groups can, like other alkylating agents mentioned, be prepared separately and used as such in the process of the invention. The alkylating agents needed can also be prepared in situ, alkylating agents containing suiphonato grouips for example from alcohiols and lialogenosulphonyl compounds.

Le A 29 700-Fi" 12 In the process of the invention, for example, from 0.01 to 10,000 equivalents of carbon dioxide can be used per equivalent of amine used. Preferably this ratio is from 0.5 to 1,000:1, in particular from 1 to 10:1.

In the process of the invention, for example, from 0.01 to 10,000 equivalents of alkylating agent can be used per equivalent of amine used. Preferably this ratio is from 0.3 to 100:1, in particular from 0.4 to 10:1. The alkylating agent can be used in a substantial excess, particularly in the case of lesse reactive alkylating agents, and can then optionally also serve as solvent.

It is an essential feature of the present invention that it is carried out in the presence of one or more basic compounds of the elements lithium, sodium, magnesium, potassium, calcium, rubidium, strontium, caesium, barium and/or of ammonium. Possible basic compounds are, for example, basic salts, oxides, hydrides and hydroxides. Examples are: lithium hydride, sodium hydride, potassium hydride, calcium hydride, lithium hydroxide, sodium hydroxide, potassium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium peroxide, potassium oxide, potassium peroxide, calcium oxide, barium oxide, magnesium oxide, strontium oxide, lithium carbonate, lithium hydrogen carbonate, sdium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, rubidium carbonate, rubidium hydrogen carbonate, 20 caesium hydrogen carbonate, caesium carbonate, lithium cyanide, sodium cyanide, potassium cyanide, rubidium cyanide, ammorium hydrogen carbonate, ammonium carbonate, ammonium carbamate, potassium sulphite, potassium hydrogen sulphide, sodium sulphide, sodium hydrogen sulphide and/or naturally occurring or synthetic mixtures containing them, such as for example dolomite or magnesium oxycarbonate and/or compounds which contain sodium or potassium metal in dispersed form on the corresponding carbonates.

Preferred compounds are alkali metal carbonates and/or hydrogen carbonates, very particular preference being given to potassium carbonate.

The basic compounds can be used in anhydrous form or, as far as salts which crystallize with water of hydration are concerned, in hydrated form. Use of anhydrous compounds is preferred.

Le A 29 700-FC 13 ~11~11 1 The basic compounds can, for example, be used in amounts of from 0.5 to 10 mol per mole of amine used. Preferably this amount is in the range from 0.8 to 5 mol, particularly preferably in the range from 1 to 2.5 mol, in each case per mole of amine used.

The process of the invention can optionally be carried out in the presence of auxiliary bases, i.e. in the presence of further bases, for example in an amount of less than 0.5 mol, with respect to the base used.

Examples of such auxiliary bases are: halides of alkali metals, zeolites, potassium Sacetate, potassium formate, sodium acetate, titanium alkoxides, titanic amides, amidine bases or guanidine bases such as 1,5-diazabicyclo(4.3.0)non-5-ene (DBN).

1,8-diazabicyclo(5.4.0)undec-7-ene (DBU), 7-methyl-1,5,7-triazabicyclo(4.4.0)dec- (MTBD), cyclohexyl-tetrabutylguanidine, cyclohexyl-tetramethylguanidine, S00 N,N,N,N-tetramethyl-1,8-naphthalenediamine, pentamethylpiperidine, N,N-dimethyl-aminopyridine, N-butyl-tetraethylguanidine, N-t-butyl-N'-N'-diethylformamidine, tetramethylguanidine, tetraethylguanidine, N-t-butyl-N',N'-dimethylacetamidine, N-cyclohexyl-tetraethylguanidine and N-t-butyl-tetraethylguanidine and also 1,4-diazabicyclo(2.2.2)octane (DABCO), tertiary amines such as triethylamine, trimethylamine, N-methylmorpholine, pyridine and tetramethylethylenediamine, primary and secondary amines having the same structure as the amine 20 used in the reaction, alkyl and aryl metal compounds such as butyl-, methyl-, phenyl- and neophyl-lithium, and also Grignard reagents.

In general, it is advantageous to carry out the process of the invention in the presence of solvents. Solvents are advantageously used in such an amount that the reaction mixture remains readily stirrable during the whole process. Possible solvents,are, for example: hydrocarbons such as petroleum ether, benzene, toluene, chlorobenzene, dichlorobenzene, hexane, cyclohexane, methylcyclohexane, pentane, heptane, octane and industrial hydrocarbon mixtures, for example socalled white spirits containing components with boiling points in the range of, for example, from 40 to 250 0 C, ethers such as dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, methyl t-butyl ether, tetrahydrofuran, 1,4-dioxane and polyethers of ethylene oxide and/or propylene oxide, amines such as trimethyl-, triethyl-, tripropyl-, tributylamine, N-methylmorpholine, pyridine and tetramethylethylenediamine, esters such as methyl, ethyl and butyl acetate, and also dimethyl, dibutyl Le A 29 700-FC 14and ethylene carbonate, nitro-compounds such as nitromethane, nitroethane, nitropropane and nitrobenzene, nitriles such as acetonitrile, propionitrile and benzonitrile and also compounds such as tetrahydrothiophene dioxide and dimethyl sulphoxide, tetramethylene sulphoxide, dipropyl sulphoxide, benzylmethyl sulphoxide, diisobutyl sulphoxide, dibutyl sulphoxide, diiosamyl sulphoxide, ketones such as acetone, methyl butyl ketone and methyl ethyl ketone, liquefied carbon dioxide, amides such as hexamethylenephosphoric triamide, N-methylpyrrolidone, N-methylcaprolactam, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidine, octylpyrrolidone, octylcaprolactam, 1,3-dimethyl-2-imidazolinedione, dimethylformamide, dimethylacetamide, formamide, diethylformamide, N-formylpyrrolidine, N-formylmorpholine, N-formylpiperidine, N,N'-1,4-diformylpiperazine, dipropylformamide and dibutylformamide. Also suitable are dimethylsulfone, 2oo diethylsulfone, dipropylsulfone, dibutylsulfone, dipentylsulfone, dihexylsulfone, methylethylsulfone, ethylpropylsulfone, ethylisobutylsulfone, 3-sulfolane and 15 pentamethylenesulfone.

The process of the invention can also be carried out without solvent, particularly when, instead of solvent, auxiliaries suitable for phase transfer reactions are added, o. for example quaternary ammonium salts, polyvinylpyrrolidone, trioctylphosphine oxide and/or acetylacetone.

20 Auxiliaries such as cryptands, for example crown ethers or polyethers as complexing agents, may optionally be added to the solvents.

Mixtures of solvents can of course also be used in the process of the invention.

Preferred solvents are dimethylformamide and dimethylsulphoxide and mixtures of these with other solvents mentioned.

The process of the invention is generally carried out in such a way that the basic amine and the carbon dioxide are first combined in the presence of a basic compound of the elements mentioned and allowed to react. It is advantageous to add the alkylating agent only when the reaction of the amine with the carbon dioxide is complete or largely complete. The progress of the reaction of the amine with the carbon dioxide can be monitored, for example, by the degree of heat evolution.

Le A 29 700-FC 1.5 Ir_ Both steps of the process of the invention can be carried out, for example, at temperatures of from -50 to +180 0 C. Temperatures are preferably in the range from -30°C to +150 0 C, particularly in the range from -10 0 C to +100 0

C.

The pressure is not critical in the process of the invention. It can in principle be carried out at atmospheric pressure, but increased or reduced pressure is also possible. It is preferable to work at atmospheric pressure or at pressures up to bar. At higher temperatures it is advantageous to use increased pressure, optionally even above 15 bar.

SThe process of the invention can be carried out under a carbon dioxide S 10 atmo 1oere, but also in an atmosphere containing carbon dioxide and other, preferably inert, gases. If liqued carbon dioxide is used, then the reaction is preferably carried out in an closed vessel at the autogenous pressure which is Sdeveloped.

The process of the invention has a number of surprising advantages. It allows the preparation of carbamates in a technically simple, economically advantageous \manner, avoiding the use of phosgene, chlorine, formic esters, isocyanates, carbamoyl chlorides and carbonates, which in many cases require very considerable expenditure for plant safety. It can be used to prepare N,Ndialkylated, highly O-reactive alkenes and alkines which are not obtainable, or obtainable only with great difficulty, by other means, such as Bu 2

N-CO-OCH

2 -C-C-H (see Example 13). It can be carried out under mild reaction conditions and the reaction mixtures can often be directly used further, for example for hydrogenations, chlorinations, brominations, oxidations, condensations and/or polymerizations.

Radioactive or labelled carbon atoms can be simply introduced into organic molecules using the process. If the carbamate produced is to be isolated in pure form, this can likewise be achieved in a simple manner, for example by separating off the mixture of salts present in the reaction mixture, stripping off the readily volatile components of the reaction mixture and then isolating the carbamate, for example by distillation or crystallization. If the reaction mixture contains unreacted amine, this can be removed as described above or by washing with dilute acid, without the carbamate formed being attacked. As the process of the invention Le A 29 700-FC 16- I I proceeds in a heterogeneous phase, it is also suitable for continuous operation, in which case solvent and base, optionally after regeneration, can then be recycled to the reaction mixture. This is particularly convenient for the solvent, since it allows direct reuse without introduction of an aqueous phase in the work-up.

Carbamates are important substances in the chemical industry which are used, for example, as intermediates for active ingredients or as active ingredients in plant protection (in particular for insecticides, pesticides, fungicides and herbicides) and in the pharmaceutical area. They can also serve as intermediates for plastics, paints and polymers. Isocyanates can be obtained from carbamates by thermal S 10 elimination. The process of the invention can also be applied to the removal of undesired halogen-containing organic materials from waste gases and liquid and solid residues, and also for rendering harmless halogencontaining organic weapons (as mentioned, for example, in Klimmek et al., Chemische Gifte und Kampfstoffe [Chemical Poisons and Weapons], Hippokrates Verlag Stuttgart 1983, p. 27 ff.).

S 15 Examples are the removal of methyl chloride and chlorodimethyl ether from waste gases or the disposal of bromoacetone, bromobutenones, chloroacetophenones, mustard gas and nitrogen mustard.

The process of the invention can also be used to protect primary or secondary amines for further reactions, by conversion to carbamates, and afterwards again g* 20 liberating the primary or secondary amines from these. This protective group technique is particularly important in the area of protein chemistry (see for example T.W. Greene, Protective Groups in Org. Synthesis. Wiley-Interscience, New York 1981, pp. 223-249). Some particularly important carbamates, which can advantageously be prepared according to the invention, are as follows: 3-methyl-2oxalidone, N-phenyl-carbamic acid, ethyl N-methyl-N-phenylcarbamate, ethyl Nethyl-N-phenylcarbamate, carbendazim, isopropyl 3-chlorocarbanilate, 4-nitrophenyl-methylurethane, 1,3-propanediol-2-methylone-bis(methylcarbamate), 2- [(methoxycarbonyl)-.methyl-amino]-benzoic acid N-methylisatate, methyl 7hydroxy- -naphtilalenecarbamate, ethyl diphenylcarbamate, 3-ethoxycarbonylaminophenyl N-phenylcarbamate, mrethyl N-[3-[N-(3-methylphenyl)-carbonyl]phenyl]-carbamate, CH 3

-N(-CH

2

CH

2

-O-CO-NH-C

6

H

5 2 N-L-ax-aspartyl-L-phenyl alanine-l-methylester-N-benzyl carbamate, aspartyl benzylester-N-benzyl carbamate, aspartyl methylester-N-benzyl carbamate, aspartyl ethylester-N-benzyl carbamate, aspartyl acid-N-benzyl carbamate, and the carbamates mentioned in Le A 29 700-FC 17

I

K.H. Buechel, Pflanzenschutz und Schadlingsbekampfung [Plant Protection and Pest Control], Georg-Thieme-Verlag, Stuttgart, 1977, in the chapters Insecticides, Herbicides, Fungicides, Nematocides, Acaricides and Bactericides, as well as carbamates described in EP 289,842 and DE 4,026.966.

Also carbamates of the type described in WO 93/7116 and EP 582,902 (see Examples 33 and 45 of the present description) can be produced according to the present invention. The corresponding benzyi compounds with leaving groups as described above and the corresponding amines can be used as educts in this case.

Also carbamates of the type described in EP 560,424 can be produced according to the present invention, especially the compound designated 1 to 3, 6 to 10, 12 and 14 to 17, as well as similar compounds with structures of the carbamate type :*as described in EP 560,424. The starting materials then are, for example, benzyl or aliphatic compounds with leaving groups as described above and the corresponding amines.

Also carbamates of the type described in EP 335,297 and in EP 366,189 and in Keith et al., Spec. Publ. R. Soc. chem., 119, 79 (1993), and in literature cited there can likewise be prepared. Especially compounds using ciprofloxacin as a starting material, e.g. compound 8 cited in Keith et al., can be prepared easily.

The starting materials are esters of ciprofloxacin or related derivatives of quinolones and cephatosporius in their protected form (see the literature mentioned above) and with leaving groups as defined above, preferred activated esters as tosyl or mesyl esters.

Carbamates of the type described in U.S. 5,210,224 (antibiotic lankacidines) can also likewise be prepared. In this case the corresponding mesyl- or tosyl- or other above stated acyl leaving groups are bond to the lankacidine instead of the carbonate group given in U.S. 5,210,224 and is reacted with CO 2 and an amine as described above. The products are the same as given in U.S. 5,210,224 and might be others depending from the amine used.

Le A 29 700-FC 18 I L Examples The bases used in the examples (often potassium carbonate) were dried at 150°C and 15 mbar for 14 hours and powdered. Solvents used (often dimethylformamide or dimethyl sulphoxide) were dried with a molecular sieve of 3 A. All reactions were carried out with a steady slow stream of carbon dioxide over the reaction mixture.

Example 1 Cinnamyl N-methyl-N-9-fluorenylcarbamate 5.0 g of N-methyl-N-9-fluorenylamine, 20.0 g of potassium carbc'ate and 100 ml of dimethylformamide (abbreviated to DMF below) were admixed with 40 g of dry ice and after 1 hour at 25 0 C under a carbon dioxide atmosphere 4.69 g of cinnamyl chloride were added. The mixture was stirred for a further 1 hour at 25 0 C and 5 hours at 50 0 C, then separated from the solids, the volatile components were driven off under reduced pressure, the concentrate was extracted with dichloromethane/water and the extract was chromatographed on silica gel with toluene and an ;.creasing ethyl acetate content. 4.96 g (54 of theory) of the desired product having a melting point of from 108 to 109 0 C were obtained. In addition, 0.61 g (8 of theory) of N-methyl-N-9-fluorenyl-N-cinnamylamine having a melting point of from 85 to 89 0 C were obtained.

Example 2 Cinnamyl N-methyl-N-9-fluorenylcarbamate-13C Example 1 was repeated but, instead of using dry ice, 1 3 C0 2 (produced from barium carbonate- 13 C, 88 and sulphuric acid) was blown in. The yield was 3.14 g (34 of theory). The 13C-NMR spectrum showed a great increase in intensity of the carbamate- 1 3 C at y 157-158 ppm..

Le A 29 700-FC 19

IU

Example 3 4-tert.-Butylbenzyl N-methyl-N-9-fluorenylcarbamate in 100 ml of DMF and 20.0 g of potassium carbonate were admixed with 6.99 g of 4-tert.-butylbenzyl bromide, stirred for 2 hours at 250C and 8 hours at 50°C and worked up as described in Example 1. 3.4 g (38 of theory) of N-methyl-N-9-fluorenyl-(4-tbutylamine) having a melting point of from 92 to 940C were obtained, and also 4.02 g of an oil which contained about 80 by weight of the desired material.

The IR spectrum showed a characteristic band (CO bending) at 1,685 cm Exan:ple 4 10 Cinnamyl N-methyl-N-(1-naphthylmethyl)carbamate S" 8.5 g of N-methyl-N-(1-naphthylmethyl)-amine (obtained from the hydrochloride by shaking with sodium hydroxide, extraction and distillation using a bulb tube), 38.43 g of potassium carbonate and 200 ml of DMF were treated with carbon dioxide gas for 1 hour at 250C, then 8.34 g of cinnamyl chloride were added, the mixture was stirred for 1 hour at 250C and 8 hours at 500C and then worked up as described in Example 1. 7.23 g (44 of theory) of the desired material were obtained (yH: 4.83 ppm, 4.97 ppm). In addition, 0.83 g (6 of theory) of Nmethyl-N-(1-napthylmethyl)-cinnamylamine were isolated.

Example 20 Cinnamyl N-methyl-N-phenylcarbamate 5.35 g of N-methylaniline, 38.43 g of potassium carbonate, 200 ml of DMF, fed-in carbon dioxide and 8.34 g of cinnamyl chloride were reacted as described in Example 4 and worked up as described in Example 1. The yield of the desired product was 1.61 g (12 of theory). The 'H-NMR and 13 C-NMR spectra showed the following characteristic signals: yH: 4.76 and 3.3.2 ppm and yC: 155.4 ppm.

Le A 29 700-FC 20 Example 6 Cinnamyl N,N-dibutylcarbamate 20.0 g of dibutylamine, 37.73 g of potassium carbonate and 100 ml of DMF were treated with carbon dioxide gas (exothermic reaction up to about 45 0 23.64 g of cinnamyl chloride were then added dropwise at 10 0 C and the mixture was stirred for 1 hour at 25 0 C and 4 hours at 50 0 C. After working up as described in Example 1, 9.86 g of the desired product and 0.56 g (2 of theory) of dibutylcinnamylamine were isolated. Characteristic signals in the 'H-NMR spectrum were at 4.73 and 3.23 ppm.

10 Example 7 **Phenylacetyl N,N-dibutylcarbamate 20.0 g of dibutylamine, 37.73 g of potassium carbonate and 100 ml of DMF were combined as described in Example 6 and treated with carbon dioxide gas for 1 hour at 25 0 C, then admixed at 10 0 C with 23.95 g of a-chloroacetophenone and 15 the mixture stirred for a further 1 hour at 25 0 C and 4 hours at 50 0 C. The work-up proceeded by extraction with 5 by weight strength aqueous hydrogen chloride and ethyl acetate and distillation in a bulb tube. At a boiling point of 145°C at "0.1 mbar 29.1 g of the desired product (62 of theory) were obtained. The characteristic signals in the 'H-NMR spectrum were at 5.31 and 3.28 ppm.

Example 8 Example 7 was repeated, but using only half the amount of each material, using dimethyl sulphoxide (abbreviated to DMSO below) instead of DMF and stirring for 6 hours at 25 0 C. Subsequent gas chromatographic examination of the reaction mixture gave a 98.4 yield of the desired product based on the conversion.

Le A 29 700-FC -21 Example 9 3-Oxo-2-ketobutyl N,N-dibutylcarbamate The procedure was as in Example 7, but 23.73 g of ethyl bromoacetate were added instead of 2-chloroacetophenone and the mixture was stirred for 1 hour at 25 0 C and 3 hours at 50 0 C. At a boiling point of 100 0 C at 0.1 mbar 5.0 g of the desired product (12 of theory) were isolated. The characteristic signals in the 1 H-NMR spectrum were at 4.60, 4.21 and 3.25 ppm.

Example The procedure was as in Example 9, but only half the amount was used and DMSO was used instead of DMF. The yield (gas chromatography, by area) after 4 hours reaction time was 52 based on the conversion. The conversion was 90 Example 11 Propargyl N-butylcarbamate 15 30 g of butylamine, 100 g of potassium carbonate and 160 g of DMF were treated with carbon dioxide gas (exothermic reaction up to 66 0 After 1 hour 33.68 g of 3-chloropropine were added at 15 0 C and the mixture stirred for 1 hours at 25 0

C

and 3 hours at 50 0 C. The mixture was then worked up as described in Example 7.

2.86 g of the desired product (4 of theory) were obtained.

Example 12 5.66 g of butylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were admixed with 5.77 g of propargyl chloride after treatment for 1 hour with carbon dioxide gas at 25 0 C and the mixture was stirred for 4 hours at 25 0 C. Otherwise the procedure was as described in Example 11. The yield of propargyl N-butylcarbamate was 87 based on the conversion (gas chromatography, by area).

Le A 29 700-FC 22 Example 13 Propargyl N,N-dibutylcarbamate 100 g of dibutylamine, 189.0 g of potassium carbonate and 500 ml of DMF were treated with 440 g of carbon dioxide in a 3 1 stainless steel autoclave and subsequently heated to 1000C for 30 minutes. After cooling to 500C, 60.0 g of propargyl chloride were added at a pressure of 75 bar and the temperature maintained at 50°C for a further 6 hours. After depressurization the mixture was filtered with suction, the filtercake washed with 1 1 of methylene chloride and the organic phase distilled. Two fractions containing the desired product were collected. 1st fraction: boiling point from 55 to 95°C at from 1.3 to 1.5 mbar: 11.41 g (of which 50 by weight was the desired product). 2nd fraction: boiling point from 97 to 980C at 1.4 mbar: 107.53 g (of which 98.8 by weight was the desired product). This corresponds to a yield of 69.2 of theory. Characteristic signals in the 1 H-NMR spectrum were at 4.68, 3.23 and 2.43 ppm.

Example 14 Butyl N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 70 ml of DMSO were admixed with 7.17 g of butyl chloride after treatment with carbon dioxide gas for 1 hour. After 15 hours at 250C the formation of the desired product in a 20 yield of 42.1 was determined by gas chromatography. The mass spectrum showed M at 207.

Example Benzyl N,N-dibutylcarbamate g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour (slightly exothermic reaction). After addition of 9.83 g of benzyl chloride the mixture was stirred for 29 hours at Analysis by gas chromatography and mass spectroscopy indicated that the desired Le A 29 700-FC 23

I

I

product was then present in a 95.5 yield. M 263. After working up as in Example 1 18.4 g of product (90 of theory, 96 pure) were obtained.

Example 16 O-[3-Methoxycarbonyl-2-methoxyprop-2-enyl] N,N-dibutylcarbamate 10 g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour (slightly exothermic reaction) and 12.75 g of methyl 4-chloro-3-methoxy-2-butenoate were then added. After stirring for 45 hours at 25 0 C the desired product was present in the reaction mixture in a yield of 92.4 according to gas chromatographic and mass spectroscopic 10 examination. The mixture was filtered with suction and the residue was concentrated with a rotary evaporator, taken up with ethyl acetate and washed with 5 strength aqueous hydrogen chloride to give 26.75 g of 79.4 desired product *i *(90.9 of theory), remainder dimethyl sulphoxide. The 1 H-NMR spectrum showed the characteristic signals at 5.23, 5.10 and 3.20 ppm.

Example 17 cis/trans-O-(3-methoxylcarbonylprop-2-enyl) N,N-dibutylcarbamate 10.0 g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour (exothermic reaction). 16.32 g of ethyl 4-bromocrotonate (85 were then added. After stirring for 45 hours at 25°C the desired product was found in a yield of 23.8 of theory, according to gas chromatographic and mass spectroscopic analysis. M 271, cis/trans mixture about 1:2.

Example 18 Tributyl carbamate 10.0 g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour at 25 0 C (exothermic reaction). After addition of 10.62 g of butyl bromide and stirring for 45 hours at 25 0 C the desired Le A 29 700-FC 24product was found in an amount of 76.0 of theory, according to gas chromatographic and mass spectroscopic analysis. M 229.

Example 19 Benzyl N-butylcarbamate 5.66 g of butylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour at 25 0 C. After addition of 9.81 g of benzyl chloride and stirring for 45 hours at 25 0 C gas chromatography and mass spectrometry showed the desired product to be present in a yield of 87.2 of theory, based on a conversion of 78 M 207. After working up as described 10 in Example 16, 14.7 g (73 80 pure) of the desired molecule were obtained.

yG: 5.09 and 3.17 ppm.

*Example N-Methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO S 15 were treated with carbon dioxide gas for 1 hours at 25 0 C. 9.81 g of benzyl chloride were then added and after stirring for 45 hours at 25 0 C gas chromatographic and mass spectroscopic examination showed the desired product to be present in a yield of 56.2 of theory (M 241). In addition, N-methyl-N- .o phenyl-benzylamine had been formed in a yield of 37.0 of theory. After working up as described in Example 1, 7.8 g (42 of the desired product were isolated. yH: 5.15 nd 3.30 ppm.

Example 21 Propargyl N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour at 25 0 C. 5.78 g of propargyl chloride were subsequently added and the mixture stirred for a further 45 hours at After a conversion of 76 gas chromatographic and mass spectroscopic Le A 29 700-FC 25 examination showed the desired product to be present in a yield of 74.4 of theory 189). In addition, N-methyl-N-phenyl-N-propargylamine had been formed in a yield of 20.3 of theory. After working up as described in Example 16, 7.7 g (52 80 pure) of the desired product were isolated. IR: 1705 cm-, yH: 4.71 ppm.

Example 22 Allyl N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour and 5.93 g of allyl chloride were 10 then added. After 45 hours at 25 0 C gas chromatography and mass spectrometry showed the desired product to be present in a yield of 64.5 of theory (M a 191), based on a conversion of 31 In addition, N-methyl-N-phenyl-N-allylamine had formed in a yield of 30.3 of theory.

Example 23 15 0-[3-Methoxycarbonyl-2-methoxyprop-2-enyl] N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour at 25 0 C. 12.79 g of methyl 4- "b chloro-3-methoxy-2-butenoate were added and the mixture stirred for 45 hours at 25 0 C. The mixture was then examined by gas chromatography and mass spectro- 20 metry. The desired product was present in a yield of 63.4 of theory (M 279), together with N-methyl-N-phenyl-N-[3-Methoxycarbonyl-2-methoxyprop-2-enyl]amine. After working up as described in Example 1, 7.1 g (33 of the desired product (yH: 5.27, 5.09, 3.67 and 3.31 ppm) with a melting point of 49-50°C were isolated, together with 1.85 g of methyl N-methyl-N-phenyl-4-(3-methoxy)-buten- 2-oate.

Le A 29 700-FC 26 -c I Example 24 Propargyl N,N-dibutylcarbamate 10.0 g of dibutylamine, 18.87 g of potassium carbonate and 250 ml of DMSO were treated with carbon dioxide gas for 1 hour at 25 0 C. 5.78 g.of propargyl chloride ere then added in one portion and the mixture stirred for a further 4 hours. Gas chromatographic analysis showed the desired product to be present in a yield of 99.4 of theory. In addition, N,N-dibutylpropargylamine had been formed to the extent of 0.6 of theory.

Example *i 10 Propargyl N,N-dibutylacarbamate S* 200 g of dibutylamine, 378.12 g of potassium carbonate and 4000 ml of DMSO were treated with carbon dioxide gas for 150 minutes at 100 mbar superatmospheric pressure (exothermic reaction up to about 35 0 C) and then admixed with 115.5 g of propargyl chloride (95 pure). After 27 hours at 25 0 C the mixture 15 was filtered with suction and distilled. Apart from the fractions which distilled over at temperatures up to 68 0 C at 8 mbar and contained mostly DMSO (together with 57 g of the carbamate), 215 g of the desired product were obtained in a purity of 99 and with a boiling point of 85-95°C at from 0.6 to 0.9 mbar. This corresponds to a total yield of 272 g (88 of theory).

20 Example 26 Allyl N,N-dibutylcarbamate 500 g of dibutylamine, 94.55 g of potassium carbonate and 250 ml of DMSO were treated with carbon dioxide gas for 1 hour and then admixed with 29.95 g of allyl chloride. The mixture was very viscous and was therefore stirred for 30 days.

During this time carbon dioxide was continually fed in and a further 14.8 g of allyl chloride was 20 days and again after 23 days. After filtering with suction and dillistation 24.95 g of allyl N,N-dibutylcarbamate were obtained (30.2 of theory). The product had a boiling point of 69 0 C at 0.1 mbar.

Le A 29 700-FC 27

M_

Example 27 Propargylsarcosine carbamate 11.9 g of sarcosine ethyl ester hydrochloride, 29.55 g of potassium carbonate and ml of DMSO were treated with carbon dioxide gas for 1 hour and then admixed with 5.78 g of propargyl chloride. After 22 days the mixture was filtered with suction, diluted with methylene chloride, washed with 5 aqueous hydrochloric acid and the organic phase was concentrated. 6.3 g of a dark oil were obtained, which corresponds to 37 of theory, and the product was 91 pure.

M 199, base 126. yH: 4.72 and 4.0 ppm.

Example 28 Propargylsarcosine carbamate 8.0 g of sarcosine ethyl ester hydrochloride were treated with 20 strength aqueous sodium hydroxide solution in diethyl ether at 0°C. The organic phase was dried and concentrated. 12.81 g of potassium carbonate and 50 ml of DMSO were 15 then added. After treatment with carbon dioxide gas for 1 hour, 3.88 g of propargyl chloride were added. After 30 hours at 250C gas chromatographic analysis was conducted, which showed 84.4 of the desired product to be present.

Example 29 4-Chloro-2-butinyl N-(3-chlorophenyl)carbamate 9.89 g of 3-chloroaniline, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour at 250C and 9.54 g of 1,4dichlorobut-2-ine were then added. After 43 hours the desired product was found in 12 yield by gas chromatographic and mass spectroscopic analysis. The mass spectrum was identical with that of the known herbicide barban, which is also 4chloro-2-butinyl N-(3-chlorophenyl)carbamate.

Le A 29 700-FC 28 Example Polymer with units of the formula (-(CH)6-O-CO-N N-CO-O-) 71 g of piperazine, 450 g of carbon dioxide and 500 ml of DMSO were maintained at 100 0 C for 30 minutes and 200 g of 1,6-dibromohexane were then added at 50 0 C and the mixture was maintained at 70 0 C for 10 hours. After depressurization the mixture was concentrated on a rotary evaporator and subsequently extracted with 3 1 of methylene chloride. The organic phase was again concentrated to give a water-soluble polymer with the following parameters: 10 M w 1057 g/mol, u 0.68

M

n 630 g/mol

M

z 1920 g/mol, u z 0.82.

The parameters were determined by GPC.

Example 31 i. 15 Polymer with units of the formula (-CHCHi-O- CO N N-CO-O 49.1 g of piperazine, 423 g of potassium carbonate, 1250 ml of DMSO and 200 g of carbon dioxide were heated to 100 0 C for 30 minutes in a stainless steel autoclave and 100 g of ,a-dichloro-p-xylene were then added. After 6 hours at 50 0 C and a further 6 hours at 80 0 C, working up as in Example 30 gave a polymer whose parameters were determined as described in Example M, 2443 g/mol, u 1.49 Mn 982 g/mol M 4727 g/mol, u z 0.93.

Le A 29 700-FC 29

M

Example 32 0-4-(3-Methoxycarbonyl-2-methoxyprop-2-enyl) N-3-pyridylcarbamate 7.29 g of 3-aminopyridine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour and then admixed with 15.55 g of methyl 4-chloro-3-methoxy-2-butenoate. After 116 hours at 25 0 C, analysis by gas chromatography and mass spectroscopy showed 43 of theory of the desired product. M 4 266, base: 121).

Example 33 Compound identical with that of Example 2/2 in WO 93/7116 S 10 1.54 g of 3-trifluoromethyl-N-methylaniline, 150 ml of DMSO and 4.87 g of potassium carbonate were treated with carbon dioxide gas for 2 hours at 1.1 bar and 2.5 g of methyl 2-(2-bromomethylphenyl)-3-methoxyacrylate was then added and the mixture was stirred for 6 days at 25 0 C. After working up as in Example 1, 2.2 g (59 of theory, 86 pure) of the desired molecule were obtained. The 'H- 15 NMR spectrum of the compound prepared was identical with that known from WO 93/7116.

Example 34 D-glucopyranosyl-(dibenzylcarbamate)-tetraacetate mixture of 4.80 g (0.0243 mol) dibenzyl amine, 40 mi of dimethylsulfoxide and 6.72 g (0.0486 mol) of potassium carbonate was stirred for one hour at during which a constant stream of carbon dioxide was passed through the apparatus. Then 10.0 g (0.0243 mol) oc-D-glucopyranosylbromide-tetraacetate (97 pure) was added and the mixture was stirred for additional 28 hours followed by filtration and evaporation of the solvent. The remaining oil was chromatographated using KG 60 silicon gel and toluene as a solvent. The main fraction crystallized after removing the solvent, yield 5.87 g, m.p. 115-116°C. In the 13C-NMR four signals due to acetate (170.6, 170.1, 169.4, 169.2 ppm) and one due to carbamate (154.3 ppm) were observed.

Le A 29 700-FC 30 I Example Propan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium/carbonate and 200 ml of DMSO were admixed with 7.17 g of chloroacetone after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at 25 0 C the formation of the desired product in a yield of 89 was determined by gas chromatography. The mass spectrum showed MI 229.

Example 36 3-Aza-3-ethyl-pentan-2-on N,N-dibutylcarbamate 10 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO were admixed with 11.59 g of N-(2-chloroacetyl)-diethylamine after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at 25 0 C the formation of the desired product in a yield of 99 was determined by gas chromatography. The mass spectrum showed M 286.

S 15 Example 37 1-(Ethoxycarbonyl)propan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO were admixed with 12.75 g of ethyl 2-chloroacetoacetate after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After hours at 25 0 C the formation of the desired product in a yield of 46 was determined by gas chromatography. The mass spectrum showed M 301.

Le A 29 700-FC 31 Y I _r, Example 38 1-(Dimethylaminocarbonyl)propan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO were admixed with 12.67 g of dimethyl-2-chloroacetoamide after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at 25 0 C the formation of the desired product in a yield of 71 was determined by gas chromatography. The mass spectrum showed M 300.

Example 39 l-Acetylpropan-2-on N,N-dibutylcarbamate 10 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO were admixed with 10.35 g of 3-chloro acetylacetone after treatment with carbon Sdioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at the formation of the desired product in a yield of 47 was determined by gas chrornatgrap'iy The mass spectrum showed M 271.

15 Example Propargyl N-methyl-N-benzyl carbamate 88.0 g of N-methyl-N-benzylamine, 200.73 g of potassium carbonate and 750 ml of DMSO were admixed with 54.18 g propargyl chloride after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure.

After 48 hours at 25 0 C the mixture was filtered and distilled. At a boiling point of 123'C at 0.9 mbar 90.0 g of the desired product were obtained in a purity of 97 Le A 29 700-FC 32 I Example 41 ((Ph-CH 2 2 -N-C(O)-O)2-CH 2 50.0 g of Dibenzylamine, 175.4 g of potassium carbonate and 500 ml of DMSO were admixed with 88.2 g of methylene-bromide after treatment with carbon dioxide gas for 1 hour at 70 0 C in an autoclave at about 30 bar pressure. After 16 hours at 70 0 C the mixture was filtered and the solvent was evaporated. The remaining solid was washed with hexane and dried. Melting point 86-89 0 C, yield: 86.7 g (64.4 of theory).

Example 42 10 Example 41 was repeated but using instead of methylene bromide methylene chloride (86.3 g) and 1.66 g of potassium iodide. Yield: 65.6 g, 52 of theory.

S.Example 43 Benzyloxycarbonyl-nipecotinic acid ethylester 25 g of ethyl nipecotinic acid ester, 43.95 g of potassium carbonate and 200 ml of DMSO were admixed with 20.4 g of benzyl chloride after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 9 days at 25 0 C the mixture was washed with 5 by weight strength aqueous hydrogen chloride and ethyl acetate and dried with sodium sulfate. After removing the solvent in vacuo the remaining oil was found to be the pure desired product.

20 Yield: 25.0 g, 'H-NMR data: 7.35 ppm, 5.13 ppm (only important signals given).

Example 44 (1-Naphthylmethyl)-N,N-dimethylcarbamate 10.0 g of a reaction product of 2 mol dimethylamine and 1 mol CO, (sold as "Dimcarb" by Fa. Schuchardt, Germany), 41.19 g of K 2

CO

3 and 200 ml DMSO were admixed with 26.30 g (1-chlormethyl)-naphthalene after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After Le A 29 700-FC 33 I hours at 25°C the mixture was worked up as described in Example 1, 12.13 g (71 of theory) of the desired product were obtained. 'H-NM:R-data: 5.57, 2.93 and 2.86 ppm.

Example Cl

ICI

OH

3 c N O 0 O CH ,O

CO

2

CH

3

CF

3 SA solution of 40 g of sodium hydride (60 strength) in 1000 ml dimethylformamide was brought together with 100 g of methyl-2-(2-methyl-4-chlorophenyl)-acetic acid methylester (see U.S. patent 4,424,394) at 20 0 C in the course of 20 minutes. After stirring for 2 hours at 2 0 C, there were added dropwise 189 g 10 dimethylsulfate and the mixture was left standing over night. Thereafter, the mixture was extracted with methylene chloride, the mixture of ice and water was added, the organic phase was separated, dried with sodium sulfate and distilled.

The boiling point was 121 to 135 0 C at 0.25 mmHg pressure. In this manner, there :were obtained 104.9 g methyl-2-(2-methyl-4-chlorophenyl)-3-methoxyacrylate.

S 15 27.37 g of this product, 350 ml tetrachloromethane and 22.45 g N-bromosuccinimide were heated to reflux for 90 minutes after having added 0.5 g of dibenzoylperoxide. After filtration and evaporation of the solvent there were obtained 24 g of methyl-2-(2-bromomethyl-4-chlorophenyl)-3-methoxyacrylate with a melting point of 48 0

C.

This compound (8.6 g) was reacted as described in Example 33 for another acrylic acid methylester thereby using 27.08 g of potassium carbonate and 8.6 g of 3trifluoromethyl-N-methylaniline. The working up of the reaction mixture was carried out as described in Example 33. The desired product was obtained in this manner in a yield of 11.01 g. The 'H-NMR-spectrum showed following signals: 7.56 ppm, s(2H), 7.47 ppm, s(2H), 7.25 ppm, dd(2H), 7.06 ppm, d(1H), 5.05 ppm, s(2H), 3.79 ppm, s(3H), 3.67 ppm, s(3H) and 3.34 ppm, s(2H).

Le A 29 700-FC 34 -1

Claims (13)

1. A process for preparing organic carbamnates from a basic amine, carbon dioxide and an alkylating agent, in which the amine is first reacted with carbon dioxide in the presence of at least one basic compound of the elements lithium, sodium, magnesium, potassium, calcium, rubidium, strontium, caesium, barium and or ammonium and the alkylating agent then added.

2. The process of claim 1, in which the basic amine used is of the formula (I) \N A N R 2/ R4 m n in which R 1 R 2 W 3 and I( are the same or different and are each hydrogen or one of the following radicals in monovalent form: CI-C 30 -alkyl, C 3 -C 30 -alkenyl, C 3 -C 30 alkinyl, C 3 -C 12 -cycl oalkyl, C 5 -C 12 -Cycloalkenyl, C 8 -C 1 2 -cycloalkinyl, C 6 -C 14 -aiyl, C 5 -C 13 -hetaryl having up 3 oxygen, sulphur and/or nitrogen atoms in the ring system, C 7 -C 20 -aralkyl, C 9 -C 20 -aralkenyl, C 9 -C 20 -aralkinyl, C 7 -C 20 -alkaryl, C 8 -C 20 alkenearyl or C 8 -C 20 -alkinearyl, which are unsubstituted or substituted from one to five times by O-C 1 -C 12 -aikyl or -C 6 -C 0 -rl, INI{ 2 NH-C 1 -C 1 2 -alkyl or -C 6 -C 10 -aryl, N(C 1 -C 2 a!kyl or aryl) 2 COO-C 1 -C 12 -alkyl or COO-C 6 -Cl 0 -aryl, CONH 2 CONI{-C 1 -C 1 2 -alkyl, :00: 20 CON(C 1 -C 12 -alkyl) 2 halogen, OP(O-C 1 -C 12 -alkyI or -C 6 -C 1 0 -aryl) 2 Si(C 1 -C 12 alkyl and/or C 6 -Cl 0 -aryl) 3 Si(O-C 1 -C 12 -alkyl and/or C 6 -C 10 -aryl) 3 Si(C,-C, 2 -alkyl or -C 6 -C 1 0 -aryl)(O-C 1 -C 12 -alkyl and/or O-C 6 -C 1 0 -aryl) 2 Si(C 1 -C 2 -alkyl and/or C 6 -C 1 0 -aryl) 2 (O-C 1 -G 12 -alkyI or O-C 6 -Cl 0 -aryl), OS(C 1 -C 1 alkyl or C 6 -CI 1 0 ay), 0 2 S(C 1 -C 1 2 -alkyl or C 6 -Cl 0 -aiyl), CHO, CN, C(O-C 1 -C 12 -alkyl or -C 6 -C- 10 -aryl), .OC(C 1 -C 1 2 -alkyl or C 6 -Cl 0 -aryl), NO 2 CF 3 OCF 2 H, OCFI OCE CF3 OCH 2 CF 3 OCO(C 1 -C 1 2 -alkyl or C 6 -Cl 0 -aryl), HI4CO(C 1 -C 1 2 -alkyl or 6CO aryl), OP(C 1 -alkyl orC- 10 -aryl) 3 POC- 10 aklo -C 6 -G 10 -aryl)2 (C,-C 12 -alkyl or C 6 -Cl 0 -aryl) I 36 and/or can optionally be interrupted by oxygen or sulphur atoms or by N(C,-C 1 2 alkyl or C 6 -Clo-aryl) groups, where R' and R 2 or R 3 and R 4 can, in each case together, also be one of the above-defined radicals, albeit then in divalent form, or R 3 and R 4 can together be a from 3- to 10-membered alkyl ring, which can optionally be substituted with one or two CI-Clo-alkyl groups and/or optionally be interrupted by one or two oxygen, sulphur and/or nitrogen atoms, A is hydrogen or a radical as defined for R 1 although in divalent form, m is zero or an integer from 1 to 10 and n is an integer from 1 to with the provisos that a) R 1 R 2 R 3 and R 4 are not radicals which contain an isolated a,p multiple bond, b) in the case of m an integer from 1 to 10, at least one of the S 15 radicals R, R 2 R 3 and R 4 is hydrogen, c) in the case of A hydrogen, m is zero and Sd) in the case of A hydrogen, R 3 and R' are not also simultaneously hydrogen.

3. The process of claim 2, in which the basic amine used is of the formula (1) 20 in which R 2 R 3 and R 4 are the same or different and are each hydrogen or one of the following radicals in monovalent form: Ci-C 1

4-alkyl, C 3 -Clo-alkenyl, C 3 -Clo-alkinyl, C 3 -C 12 -cycloalkyl, Cs-C 7 cycloalkenyl, C 6 -Clo-aryl, Cs-Clo-hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system C 7 -C 1 2-aralkyl or C7-Clo-alkaryl, t- 37 which an unsubstituted or substituted one to five times by O-C 1 -C 6 -alkyl or -C 6 -Cl 0 -aryl, NHI, NH-Cj-C 6 -alkyl or -C 6 -C 10 -aryl, N(C 1 -C 6 -alkyl or -C 6 -C 1 0 aryl) 2 CO-C 1 -C 6 -alkyl, COO-C 6 -C 10 -aryl, CONIJ-C 1 -C 6 -alkyl, CON(C 1 -C 6 alkyl) 2 OS(C 1 -C 6 -alkyl or phenyl), 0 2 S(C 1 -C 6 -alkyl or phenyl), CHO, CN, OC(C 1 -C 6 -alkyl or phenyl), NO. C3, OCF 3 OCF 2 H, OCFH 2 OCO-(C 1 -C 6 -alkyl or phenyl) or HNCO(C 1 -C 6 -alkyl or phenyl), and/or can optionally be interrupted by oxygen or sulphur atoms or by N(C 1 -C 6 alkyl or phenyl) groups, where R' and R3 or R? and R 4 can, in each case together, also be one of the above-defined radicals, albeit then in divalent form, or W3 and TO can together be a from 5- to 7-membered alkyl ring, which can optionally be substituted with one or two C 1 -C 6 -alkyl groups and/or optionally be interrupted by an oxygen or sulphur atom or an N(C 1 -C 6 -alkyl or phenyl) group, A is hydrogen or a radical defined as preferred for in divalent form, m is zero or an integer from I to 5 and n is an integer from I to with the provisos that P3, W mnd 10 are not radicals which contain an isolated cr43 multiple bond, 20 in the case of m an integer from 1 to 5, at least one of the radicals R, R R and R is hydrogen, c) in the case of A hydrogen, m is zero and in the case of A hydrogen, l and Rare not simultaneously hydrogen. t' A *S A1 4. The process of claim 1, in which the carbon dioxide used is the usual commnercial. product, dry ice or isotopically enriched carbon dioxide. The proce- of claim 1, in. which the alkylating agent used is of the formula (II) X P 5 B(I) (R 6 -Y) in which R 5 R 6 and are the same or different and are each one of the following radicals in divalent form: C 1 -C 3 ,-alkyl, C 4 -C 12 -cycloalkyl, C 3 -C 30 -4ikenyl, C 5 -C 12 -cyclo- alkenyl, C 3 -G 30 -alkinyl, C8-C 1 2 -cycloalkinyl, C 7 -C 20 -aralkyl, C 8 -C 20 -aralkenyl, C 8 -C 20 -aralkinyl, C 8 -C 20 -alkenaryl, C 8 -C 20 -alkinaryl, C 5 -C 1 3 -alkenehetaryl or C 5 -C 13 -alkinehetaryl, the latter two each having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, where chains in the molecules can be linear, branched and/or optionally interrupted by oxygen, sulphur, N(C,-C 12 or G 6 -C 10 -aryl), CO, COO, SO, SO, or S0(0)0 or OP(C 1 -C 1 2 -alkyl or C 6 -C 10 -aryl) groups, where the groups R 6 -Y and R 7 -Z can also be hydrogen and in this case R.

5 can optionally be additionally substituted by COO(C 1 -C 1 2 -alkyl or C 6 -Cl 0 -aryl), O-c(O)-(C 1 -C 1 2 -alkyI or C 6 -Cl 0 -aryl), CON(CI-C 12 -alkyl or C 6 -Cl 0 -aryl) 2 (CH 2 -O-C(0)-C-C 1 2 alkyl or C 6 -C 10 aryl), C 6 -C 10 -aryl, C 5 -CI 1 -hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, O(C 1 -C 12 -alkyl or C 6 -C 1 0 -aryl), N(C 1 -C 1 2 -alkyl or C 6 -C 1 0 -aryl) 2 OP(OC-C 1 -C 1 2 -alkyl or C 6 -C 1 O- aryl) 2 Si(O-CI-C, 2 -alkyI or -C 6 -CI 0 -aryl) 3 Si(C 1 -C 12 -atkyl or C 6 -C 10 -aryl) 3 or halogen, o and p independently of one another are each zero or 1, B is not present if o p zero, Le A 29 700-FC -3 38 39 in the case of p 1 and o zero or p zero and o 1, B is one of the following radicals in divalent form: CH- 2 N(C,-C,2-alkyl or C 6 -Co-aryl), OP(C,-C, 2 -alkyl or C 6 -Co- aryl), phenyl, naphthyl, (CI2)q with q 2 to 30 or with r and s being the same or different and each 1 to 20 and M an oxygen or sulphur atom or an SO 2 or N(C,-Ci2-alkyl or C 6 -Clo-aryl) group, in the case of p 1 and o 1, B is one of the following radicals in trivalent form: CH, N, phenyl or naphthyl and X, Y and Z independently of one another are each a leaving group.

6. The process of claim 1, in which the alkylating agent is of the formula (II) X R in which R s is one of the following radicals in monovalent form: C-C 20 -alkyl, C 4 -C 1 2 -cyc- loalkyl, C 3 -C 30 -alkinyl, C 7 -C 2 0-aralkyl, C 8 -C 20 -aralkenyl, Cs-C 20 -alkenaryl, C 8 -C20-alkinaryl, Cs-C 1 3 -alkenehetaryl or Cs-C 13 -alkinehetaryl, the latter two each having up to 2 oxygen, sulphur and/or nitrogen atoms in the ring system and X is a leaving group.

7. The process of claim 1, in which from 0.01 to 10,000 equivalents of carbon dioxide and from 0.01 to 10,000 equivalents of alkylating agent are used *per equivalent of amine used. 20

8. The process of claim 1, in which the basic compound of the elements lithium, sodium, magnesium, potassium, calcium, rubidium, caesium, barium and/or of ammonium used is an alkali or metal carbonate and/or metal hydrogen carbonate.

9. The process of claim 1, in which the basic compound is potassium carbonate.

10. The process of claim 1, which is carried out inh the presence of at least one solvent selected from hydrocarbons, ethers, amines, esters, nitro-compounds, I 40 nitriles, tetrahydrothiophene dioxide, dimethyl sulphoxide, tetranethylene sulphoxide, propyl sulphoxide, benzylmethyl sulphoxide, diisobutyl sulphoxide, ketones, liquefied carbon dioxide, polyethers of ethylene and/or propylene oxide and amides.

11. The process of claim 1, which is carried out in the presence of dimethyl. formamide or dimethyl sulphoxide or mixtures of these with other solvents mentioned in claim

12. The process of claim 1, which is carried out at from -50 to +180 0 C.

13. A process for the production of organic carbamates substantially as hereinbefore described with reference to the examples. DATED this 1st day of March, 1996. BAYER AKTIENGESELLSCHIAFT By Its Patent Attorney DAVIES COLLISON CAVE S. S S. ,k ~I I I I Gai/m-p514E PROCESS FOR PREPARING ORGANIC CARBAMATES Abstract A process has been found for preparing organic carbamates from a basic amine, carbon dioxide and an alkylating agent, characterized in that the amine is first reacted with carbon dioxide in the presence of one or more basic compounds of the elements lithium, sodium, magnesium, potassium, rubidium, strontium, caesium, barium and/or of ammonium and the alkylating agent then added. o o r o o o Le A 29 700-US