Hi George,
Sorry about that, typo on behalf...The correct part number is IRS21844, here a link to the datasheet.

The 2181 should work as well but it differs from the 21844 in that it has separate drive inputs for the high- and low side so you need to generate the dead-time externally in order to prevent shoot thru. It has no cross conduction protection so IF you accidently get both inputs HIGH you WILL get into trouble. Another difference is that it lacks the SD-input which is handy to use for cycle-by-cycle current limit.

Let's see how you get along after sorting out the pin numbers. One thing I do wonder about though is that 1k resistor you mention. You really need to have a low impedance low inductance supply line to the chip as it drives the MOSFET gates with fairly high currents which has to be pulled from that +12V bus you say you have 1k resistor in....

12V supply straight into the chip with local low ESR bypass caps as close to the chip as possible.

Let us know how it goes and again, sorry about the typo on the partnumber.

/Henrik.