Use of free radical initiators in thiolcarbamate preparation

A process for the manufacture of a thiolcarbamate having the formula ##STR15## in which R.sup.1 is selected from the group consisting of --CH.sub.2 --CH.dbd.CR.sup.4 R.sup.5, --CH.sub.2 --CH.sub.2 --R.sup.6, and ##STR16## R.sup.2 and R.sup.3 are independently selected from the group consisting of the following substituted or unsubstituted groups:

• C.sub.1 -C.sub.10 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.4 alkynyl, aralkyl containing a C.sub.1 -C.sub.6 alkyl, and C.sub.3 -C.sub.7 cycloalkyl;
• wherein the substituents are independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, C.sub.1 -C.sub.4 alkoxy, and C.sub.1 -C.sub.4 alkyl;
• or
• R.sup.2 and R.sup.3 are joined to each other to form, together with the nitrogen atom, a nitrogen-containing heterocyclic ring;
• R.sup.4, r.sup.5, and R.sup.6 are independently selected from the group consisting of hydrogen and the following substituted or unsubstituted groups:
• C.sub.1 -C.sub.10 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.4 alkynyl, aryl, aralkyl containing a C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.5 -C.sub.7 cycloalkenyl, C.sub.1 -C.sub.10 alkoxy, C.sub.2 -C.sub.6 alkenoxy, C.sub.2 -C.sub.10 alkoxyalkyl, C.sub.2 -C.sub.10 alkylthioalkyl, C.sub.3 -C.sub.10 alkoxyalkenyl, C.sub.3 -C.sub.10 alkylthioalkenyl, and heterocyclic ring groups;
• wherein the substituents are independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, C.sub.1 -C.sub.4 alkoxy, and C.sub.1 -C.sub.4 alkyl;
• and
• R.sup.7 is selected from the group consisting of C.sub.1 -C.sub.5 alkylene and C.sub.3 -C.sub.5 alkenylene;
• which comprises reacting a secondary amine having the formula ##STR17## in which R.sup.2 and R.sup.3 are as defined above, with carbonyl sulfide and an unsaturated compound selected from the group consisting of
• CH.sub.2 .dbd.C.dbd.CR.sup.4 R.sup.5, CH.sub.2 .dbd.CH--R.sup.6, and ##STR18## in which R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are as defined above, in the presence of at least one free radical initiator selected from the group consisting of
• a. an azonitrile having the formula ##STR19## in which R.sup.8 and R.sup.9 are independently selected from the group consisting of C.sub.1 -C.sub.6 alkyl, phenyl, phenylalkyl containing a C.sub.1 -C.sub.3 alkyl, and C.sub.3 -C.sub.6 cycloalkyl;
• or R.sup.8 and R.sup.9 conjointly form C.sub.3 -C.sub.9 alkylene;
• b. a phosphite having the formula (R.sup.10).sub.2 POH or (R.sup.10).sub.3 P in which R.sup.10 is selected from the group consisting of C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, phenoxy, and phenylthio;
• c. a ketone in the presence of ultraviolet light, said ketone having the formula ##STR20## in which R.sup.11 and R.sup.12 are independently selected from the group consisting of C.sub.1 -C.sub.6 alkyl, phenyl, and phenylalkyl containing a C.sub.1 -C.sub.3 alkyl;
• d. a dione having the formula ##STR21## in which R.sup.13 and R.sup.14 are independently selected from the group consisting of C.sub.1 -C.sub.6 alkyl and phenyl, and n is an integer ranging from 0 to 6;
• e. a substituted or unsubstituted aromatic compound selected from the group consisting of phenanthrene, naphthalene, and quinoline;
• wherein the substituents are halo or methyl.