2_deploy_contracts.sol

var Core = artifacts.require('Core')
var Contract2 = artifacts.require('Contract2')
var Contract1 = artifacts.require('Contract1')

module.exports = async function (deployer) {
  deployer.deploy(Contract2)
  deployer.deploy(Core).then(function () {
    deployer.deploy(Contract1, Core.address, 250)
  })
}