Atmospheric pressure cyanation of dihalobutenes in the liquid phase

Claim 1

PROCESS FOR PREPARING 1,4-DICYANO-2-BUTENE BY REACTION AT ATMOSPHERIC PRESSURE OF HYDROGEN CYANIDE WITH A DIHALO ADDITON PRODUCT OF 1,3BUTADIENE WHEREIN THE HALOGEN ATOMS ARE OF ATOMIC WEIGHT BETWEEN 35 AND 80, WHICH COMPRISES HEATING IN THE LIQUID PHASE TO A TEMPERATURE OF 80* TO 105*C. UNDER ATMOSPHERIC PRESSURE A MIXTURE COMPRISING A COPPER SALT CATALYST, A CARBONATE OF A METAL OF GROUP II OF THE PERIODIC TABLE IN AMOUNT SUFFICIENT TO NEUTRALIZE THE HYDROGEN HALIDE FORMED BY THE REACTION AND TO MAINTAIN THE REACTION MIXTURE AT A PH BETWEEN 4 AND 6 THROUGHOUT THE REACTION, AND WATER IN AMOUNT BY WEIGHT AT LEAST EQUAL TO SAID CARBONATE, ADDING TO SAID AQUEOUS MIXTURE THE DIHALO ADDITION PRODUCT OF 1,3-BUTADIENE AND THE HYDROGEN CYANIDE AS THE SOLE CYANATING AGENT, THE LATTER BEING INTRODUCED DURING THE REACTION AT A CONTROLLED RATE SUFFICIENT TO MAINTAIN MODERATE REFLUX OF HYDROGEN CYANIDE BUT NOT SUBSTANTIALLY EXCEEDING ITS RATE OF REACTION WITH THE DIHALO ADDITION PRODUCT OF 1,3-BUTADIENE, AND MAINTAINING THE TEMPERATURE OF THE REACTION MIXTURE THROUGHOUT THE REACTION BETWEEN 80* AND 105*C.